Sounds to me like you could get away with a netbook.
I just got an Acer Aspire One 10.1 inch Onyx Black from Walmart with the AMD chip and the Ati 4225 graphics (384 meg) and have to say that I'm very impressed.
The one thing that made the biggest difference was moving to 2 Gig of memory which I ordered off of newegg. Once I did that, the machine run nearly as fast as my year and 1/2 old HP DV6885. For a netbook, the system really flies. It loads and compiles code fast in VS2010 and does HD video just fine(the monitor is only 1024x600) but it has a VGA and HDMI output and can play back full HD no problem.
I stopped carrying my HP as this netbook literally was able to replace my notebook. At just over 2 lbs and 350 dollars with RAM upgrade, I couldn't beat it.