I agree hard buttons are nice, which is why I have both. I have MX-850's and 650's in all the rooms for everyday use, plus I have two daughters who are kind of rough with remotes. When it comes to my theater, I like to use the touch screen, however.

I wasnt the first person to jump on board when Apple released the iPhone / iPod touch way back when, but I was given one as a Christmas present and have found a lot of cool uses for it. For instance, I have a dedicated PC (Notebook) with HDMI out going to my projector. With the iPad and iPhone, I can use the Apple Remote program to access iTunes from either device and have the iTunes interface on the screen at the same time. Also, Logitech has a free app to turn your iPhone or iPad into a wireless mouse and keyboard. So, I can kick back and control my notebook mouse over WiFi right on the projector / screen and web browse, shop on eBay etc....

I dont think the iPad will completely replace touch screens in AMX and Crestron systems, it's just nice to be able to bring up control on either device whenever you need to.