The prospect of a new iPad has motivated me to hurry up with the iPad development. Recently I got an iPad and the dev experience so far has been great. Some other considerations: Apple has been pretty good IMO in supporting old iPhone apps on the new retina displays... so it seems reasonable to assume Apple will be mindful of old iPad apps running on the new device. Also the iPad is a larger investment/purchase for most people... so I don't see all iPad owners instantly updating when the new model becomes available.

compatibility has been pretty good, so unless you were to target an app with specific new features it wouldn't affect much.

It will undoubtably have a camera, so now start making all those camera apps use the bigger screen. Same with skype, etc... I will add the ability for users of my iPad apps to use photos, take photos, etc... This was limited to the iPhone version.

More memory means will be able to do more things, load up bigger files into mem.