Then my mom got one of those HP desktops with the touch interface. I figured she'd never touch it, just use the keyboard and mouse.
When I was showing her how to do a few things, I found myself using the touch screen WAY more than I expected.
I would be very surprised if your next desktop/laptop wasn't touch enabled as well.
I don't know from experience but I can only guess how uncomfortable it would be to have to lift my arm up to have manipulate on screen objects as opposed to using a mouse and/or keyboard. Maybe I'm just lazy..
I don't think the iPad will displace this traditional method of input unfortunately. The mouse and keyboard will be around for a long time to come.
I could write a bunch of crap about the different pieces of functionality that are lacking in touch applications or the wasted screen real estate or touch interfaces in general.
But these types of articles are around the internet everywhere and this post simply isn't worth the effort to discuss.
My only point is that the desktop space and mobile space are very different and I don't see them converging.