I'm glad they never went through with the lantern thing. It was a dumb idea--or rather, as presented it was a dumb idea. The game is too far along to just suddenly decide, "hey, torches won't burn forever anymore!" Additional light sources would be cool, though, and it would be nice if we could color them now that we have colored lighting.
I guess the lantern came out during the 'throw ideas out there and see what sticks' phase of the design. Pretty redundant anyway, what with torches, glowstone, and burning netherrack.
I still think the game could use a carryable light source for exploring though. And it would be nice to have some sort of craftable lamp for lighting large areas, rather than having to set torches all over.