Have you looked at the 11z? Stock $399 (-7% EPP discount) is a 1.3GHz Celeron and a GMA 4500MHD, 160GB SATA hard drive, and an 11.6" 1366x768, 720p screen. It has HDMI out and can handle games significantly better than any of the netbook/Atom-based Minis. It may not be for you, as it is a bit bigger (read: 1-2 inches wide and deep) than the 10" Minis. And if you don't mind dropping an extra $75, you can get a true-blue dual-core Pentium in it, and without the limitations of the GPU that the 10 offers with the Z5xx series dual-core Atoms. Plus the TDP of the Pentium is only 10W, and it's 64-bit.
That's my speel, I'm done. /rant
P.S. No, I don't work for Dell :P