I wouldn´t mind if the iPhone and iPad would have exactly the same features, just like iPod Touch and iPhone has (except the phone of course). What kills me is that the iPad is so stripped down with all the cool features.
I'm not seeing that much difference between the iPhone and iPad feature-wise. The most obvious difference is the lack of camera, but other than that the only difference I'm aware of are "invisible" ones, like CPU and less RAM. Frankly, I'm not interested in those points, my iPad is FAST. What do I care if the iPhone is faster? And there seems to be some question on that point, I remember reading about some benchmark tests showing the iPad performing faster than iphone4.
Oh, and of course, there is no phone, but you aren't saying the iPad should be a phone, are you?
Software-wise, not having iOS4 means the iPad is missing a lot of features (but being jail broken, I'm not missing any major software feature

), but that will be remedied in November, when Jobs has promised that all iOS versions will be "unified."
I agree with Alex's point about how Apple may have held back the iPad because they were worried about reception, and breaking in a new product category. And I'm sure Apple will be expanding their touch screen device lineup, and we will see more and more powerful tablets in the future. But I'm not sure thinking about this as "features exclusive to the iPad" is helpful. We should just talk about what features we want to see on the iPad, and forget about the iPhone -- personally, I can't think of any feature I'd like on the iPad that won't also be useful on the iPhone. Trying to think of features only for the iPad might really be stymying the conversation.
Oh, and that reminds me, we'll just have to agree to disagree about your feeling that it's "wrong" for a tablet to be less powerful than a phone. I just don't see any reason why physical size should have any correlation to computing power.