Just the other day, Adam suggested that more bag space was always a good thing, but now Drysc tells us that's not exactly true-- even though 20-slotters are more common than ever, Blizzard has no plans to let us replace the normal 16-slot backpack anytime soon. And the reason he cites is interesting: it has nothing to do necessarily with ingame limits, but more to do with out-of-game limits. WoW has 10 million players, and if each one of those players has easily 10 alts average and each alt has a bunch of 20-slot bags and even more items in the bank, then pretty soon you're starting to talk real amounts of physical computer memory.
We don't know what that limit is (and of course it depends on how Blizzard stores their information), but Drysc tells us that it's there. And that also gives you a little hint into just how huge their operation is-- nobody else has even come close to dealing with the problem of handling inventory and stats information for ten million players and countless numbers of characters. But Drysc says Blizzard is working on it as always-- despite the technical headaches, we may see bigger backpacks soon.