When I went shopping the writer in me won. I was seduced by the 11" MBA. It's light, beautiful and very easy to type on. I'm still awaiting delivery - I ordered the I.3GHz with 250GB ssd and 8 GB RAM. The idea was to get a machine that would help me write - that was my main need. I am seriously thinking of getting an iMac to keep it company later on - or is that just overkill? In the meantime I will look out for a reasonable budget monitor I think. Something thay will run well off the Air and give pretty good colour reproduction but not costing more than about $300-350.
I found an older Apple Cinema Display on Craigslist that works well with my MBP. Give me a nice sized screen when I'm working at home - where I do most of my photo work as I don't try to edit when on the road unless needed. Check Craigslist or eBay for deals.