I chose the MBA for a few reasons over the MBP:
1. Smaller: can't emphasize this enough. Because it's smaller, I USE it much more frequently. No second thoughts on grabbing it on the way out the door, easily fits into any of my bags. Plenty sturdy.
2. Screen: supposedly the same LED technology as on the MBP, but IMHO my MBA's screen is MUCH MUCH MUCH brighter and easier to read. This was the reason to go MBA over the MB, and even the MBP.
3. Keyboard: Mild point, but imporant. With the huge touchpad (in hindsight, a very big plus; have a hard time going back to the average-sized touchpad on my wife's windows box) and smaller size, your hands can reach the keyboard easily from wherever they are on the computer. On the MBP 15", I had to reach forward. Sounds like a minor point, but in real-life conditions makes a difference. I'm also partial to the MBA chiclet keyboard, even though I loved the MBP's.
4. Power: Perfect for what I use it for. To be honest, I probably wouldn't use a laptop for intensive graphics work regardless of the power, because I have a 20" iMac which makes this type of effort much easier.
5. I put the little guy through the paces, TRYING to find a reason to go back to a MBP. Aperture? Not super-fast, but works just fine on the go. Blogging, wordprocessing, browsing, researching, Papers, email, netnewswire, itunes, HD movies on itunes...all with no problems. A mild slowing when opening multiple indesign posters while using itunes, safari, forefox, mail, preview, open office and excel with a 2nd monitor.
In the perfect world, I'd replace my iMac with a MacPro, purchase a 17inch MBP as a portable desktop and a MBA for actual travel work. But I'm sitting here writing this while watching the Bucs, doing most of what I need to do where I want to do it. Without thinking twice.
