[Note: This was posted at 1:54pm CDST, on 5/13/10.]
WHAT THEY DIED FOR
IN THE LIGHT OF LIFE GAME:
SOULFUL SACRIFICES ENERGIZING
A SOURCESTREAM MAGNETOHYDRODYNAMIC CORE,
FUELING SMOKEY'S BID TO CUT THE CHAIN THAT BINDS,
RIDING A GRAVITY-DRIVE SPACETIME-TRAVELING SHIP HOME
AS PRINCE OF DARKNESS IN THE MIRROR MATTER VERSE....
Despite the mixed reactions received to date,the Light of Life (LOL)-infused SOURCESTREAM emanating from the 'Sheol' Cave of Souls does provide us with another key piece in the puzzle that is Lost. First and foremost, the LOL reveal in 6.15 underscores the importance of SOULS in understanding the nature, purpose, and powers of the island. True to form, from the 'get-go' Darlton promised us that the ISLAND itself will be a key character unto itself, on the show. And their delivery on this promise shows no sign of abating, as.... we may well learn in the final episode that Lost SOULS are just what it takes to power the island proper....
Here I would refer back to my prior Season 6 postings-- especially the 5/6/10 Island MHD Propulsion and the 3/16/10 Recon and 3/2/10 Sundown postings--to propose not only that it is the LOL/Force provided by SOULS that powers the ISLAND and its Sourcestream, but also that the very nature of the departed (good or evil) will in no small way figuratively and literally 'color' the power water fueling the island.
As the MA'AT's scale of judgment tips toward a predominance of 'good' souls departed and resident on the island, then we should expect that the Sourcestream waters will flow CLEAR and WARM to the touch, as confirmed in the 6.15 episode. This is the very type of water imparting healing powers in the Temple spring-fed pool, an LOL 'Life Equation' (LE) infused fluid medium imparting life, health, and more....
At the other end of the spectrum, as the MA'AT's scale of judgment tips toward a predominance of 'bad' souls departed and resident on the island, we should expect that the Sourcestream waters will flow BROWN/TAINTED and COLD to the touch, much as we've seen in prior episodes when: (1) Ben summoned Smokey using the ancient fluid-drive communication and 'tube-underground-Smokey-transit' system and (2) when Sayid was 'healed' via darkside resurrection in the brown ALE (Anti-Life Equation) infused fluid infecting him with figurative and quite literal DARK ENERGY....
What may lie on the revelatory cusp of Lindelof's acknowledgment that WATER will play a key role in the series resolution and the water-related 'reveals' found in episode 6.15 is the core notion that the Sheol Cave is the SOURCE of life and death, housing both good and bad souls, with very literal correlates in the form of: (1) LOL/LE positive matter/energy-infused water associated with Good Souls, and (2) ALE negative/dark matter/energy-infused water associated with Bad Souls....
As per my Hot and Cold Pockets theory, in addition to the existence of the Sheol cave, there are multiple energy pockets found and exploited by MIB's ancient hunter band and the DHARMA INITIATIVE, and given what Dr. Robert Foot (nod to the statue, of course!) has found regarding the nature of Dark Matter/Energy in the presence of positive matter/energy, we should expect to see things get very, very COLD in those pockets where DARK MATTER/ENERGY dominate....
Thus I would propose that one very real and consequential aspect of Smokey's and Jacob's ongoing dark/light game to date is that it is most definitely in Smokey's best interest to have more and more people 'accidentally' brought to the island and die as fallen, sinful creatures, as this adds more FUEL vis-a-vis more Dark Energy SOULs to the fluid based 
and borne energy system interlaced and catacombing through the entire island....! Accordingly, Jacob's charge is to protect the LOL integrity of the island through sowing lightside seeds, as per his touching mainland excursion flashing back to the formative years of Kate, Jack, Sawyer, and the rest of the Castaway New Kids On The Block.... Yes, this would mean that each and every 'good' soul who died on the island would help his lightside cause, analogous to them contributing to the 'force'....
From this perspective, it is easy to see that in addition to higher planes of interpretation explored by myself and others to date, on a very real material/energetic literal plane, the GAME played by Smokey and Jacob may well turn out to be a struggle for control over the fundamental nature of the SOURCESTREAM ENERGY infusing throughout the island.... Smokey wants to gain freedom from an LOL lightside-dominated water-borne imprisonment through infecting it at the very SOURCE, and with each new dearly departed bad/evil SOUL that is added to the island's Sourcestream, the water becomes more and more tainted with the ALEful brownness of darkside influence, quite literally through the addition of more DARK ENERGY into the drink....
THIS may very well turn out to be a literal, subtextual, yet-to-be-disclosed reason that it is most certainly in SMOKEY's best interest to turn people to the darkside 
and THEN to have them die to the island..... Too bad he did not get SAYID's soul/energy added in the form of Dark Energy, as Sayid switched allegiances in the final moments of the sub explosion, to the LOL lightside force....
Cold pockets signify the presence and operation of DARK MATTER/ENERGY on the island, and this may help to explain why the FDW and surrounding area is so cold.... Over the long years, Smokey's grand plan may well turn out to be the transmutation of gold to lead, a mirror twin alchemical pursuit... striving to take the 'Gold' that is the Light of Life-infused island waters and turn them instead into the 'Lead' of ALEful, brown, tainted Dark/Mirror Matter waters..... All geared, of course, to his goal of returning home to... his Dark/Mirror Matter 'verse.... Heh-heh-heh....!
In short, as I proposed in my 5/6/10 Island MHD Propulsion posting, the island is a magnetic-fluid-driven engine (a ship?) quite possibly able to travel: (1) 
through SPACE via generating and manipulating MAGNETIC FIELDS, and (2) through TIME via generating and manipulating GRAVITY FIELDS, potentially opening mini-wormholes in the process.... And the deep, dark, and dire threat to which Widmore alluded in a prior episode may well turn out to be the threat of Smokey finally succeeding in recharging the island's fluid/water-based energy reserves, only through a mirror-inverted alchemical manner, as the MA'AT's scale tips toward fluid reservoirs dominated by bad souls imparting their Dark Energy, enabling Smokey to turn the warm, clear LOL waters into cold, tainted ALEful energy, ultimately enabling him to use the island's transmuted powers to return to his home as the Prince of Darkness in the Shadowlands of the Dark/Mirrormatter 'verse....
As Michael Emerson observed in a recent PopWrap interview:
"For me, the ending of the series required some analysis. It’s not given to you on a dish, neatly organized with a fancy bow put on the end of it. What it does have is a great soulfulness and the ending is human scale."
Yes, what will happen to them-- indeed, what would happen to us-- here in the positive 'regular' matter 'verse, if Smokey succeeds and the veritable cork/plug is pulled, and the Light Of Life Game is Lost, and the Sourcestream is gone....?
Time will tell....
Dr. Todd J. Hostager