Why buy a MacBook Pro 15" instead of a MacBook Air?

[Simon]

Nice to see lots of points being made in this thread. I really wish I could justify getting the Air, but it just doesn't seem to be enough of what I want to have right now. If I traveled more I might go with the Air and a second home machine, but mostly I use the convenience of a notebook to work in half a dozen places around the house without ever need to sync things between two machines.

So it looks like the 15" MacBook Pro is the way to go, since as cd34 mentioned, it will wind up being my primary machine. I've wanted to try that new trackpad and the gestures, but the nearest Apple Store is 120 miles away.

Now I need to figure out which of my useful applications will need an upgrade to run on the Intel hardware. And then I'll know how much the notebook upgrade will really cost.

Let's see... Photoshop 7.0 from 2002 probably won't work. Used to be easy to just buy Photoshop but now it seems like it's being packaged with a variety of other Adobe apps I've never used. I use Photoshop and ImageReady (a lot). I understand ImageReady is gone now, so what's the closest combo to those two without a lot of the other fluff?

Oh, and how about the new backup system, Time Machine? Would it be smart to get a new hard drive dedicated to use only by Time Machine? From what I read it seems the larger a hard drive it has to backup onto, the further back in time it can go. So, is there some multiple of the size of the notebook's hard drive that's needed to really make Time Machine useful?

I'm sure I'll think of another question or two later, but feel free to jump in early if you want.