I noticed that you also don't have to always pick up all your loot by pressing and holding the X Button. Just walking over or near it will automatically pick it up now. This new feature doesn't apply to loot chests though. You still need to hold the X Button for those.
From what I've seen and experienced Borderlands 2 is sure to blow the first one out of the water, not only in content but in just about every other category.
Borderlands 2 comes out September 18th, 2012 and is being developed by Gearbox Software and published by 2K Games.