Perfect replacement for what you usually have in game dev studios - lots of small loose files (we have about 380,000 of those) - materials, textures, shaders, models, animations, etc.
Depending on the goal you're trying to achieve, it could be a great tool, but I wouldn't diss the filesystem too much. You lose the discoverability of all your fs tools, a whole suite of APIs no longer becomes available (async IO, say), and you throw another access layer in front of your data w/ a corresponding performance drop.
Not to say that SQLite wouldn't offer lots of advantages, but I'm not sure I'd be in a huge rush to start packing all my game assets into a db unless I had some pretty convincing wins. I'd be much more likely to stick w/ the 380k in development and then pack into contiguous level binfiles before shipping. ( I'm totally armchair coding though, I admit :) )
No easier format than just reusing SQLite.