Do you like MediaCentral? I always thought that there was too much going on there and you lost the simplicity of FrontRow. I use Remote Buddy which works great as a bridge between FrontRow and EyeTV software. If I want to do anything more advanced then I use Remote Desktop for setting a recording etc...I would definitely recommend a mini, especially now with the new C2D processor, which I happen to be proud owner of. Add then $29 for a license of MediaCentral (from Equinux), and you have hardware/software much more capable than AppleTV or Frontrow. It plays virtually any file format (incl. VIDEO_TS folders), it is operated with Apple remote, it is integrated with iTunes and iPhoto, etc. With AppleTV, you are limited to playing 720p material at the best and only certain "Apple approved" file formats.
Mike, I have my mini connected via a DVI-HDMI cable to my Sony 46X2000 LCD, and the mini outputs the native 1920x1080 resolution, no problems.
Yepp, mini all the way!