What would I lose from switching from iPhone 4+ e-reader to dumbphone+iPad I'm currently using an iPhone 4 and a cheap e-reader that was given to me as a gift. I don't think I can afford both an iPhone and an iPad, so I was considering switching to a dumbphone (non-smartphone) and an iPad. What features would i lose, or miss, from making this switch - specifically in the iphone-ipad part?
It seems to me that you would spend less money overall if you just kept the iPhone and got a wifi-only iPad rather than switching phones and plans (not including that nasty early termination fee on the iPhone contracts). That is what I have now and I really like it.

But, to answer your question specifically, even taking into consideration the iOS 4 release for iPad later this year, you will be missing, at minimum, all of the camera-related functionality of the iPhone, but then there is visual voicemail and easy (and cheap) email. That's a lot to give up all things considered.