It may sound strange, but the lack of a case for the iPad 2 that mimics the official iPad 1 case is what finally tipped me into keeping hold of my iPad 1 rather than change for the iPad 2:
I absolutely love the official iPad 1 case - I tried several cases before I settled on it (including leather ones and an Otterbox Defender) and when I finally got one it was like having a new iPad - it fits beautifully, protects it perfectly and it cleans up really easily (even if it does get grubby a bit quickly, a quick wipe with a dry cloth has it looking like new again)
On top of that it weighs next to nothing, adds virtually no bulk and makes the iPad dead easy to carry