I have the 2009 version of the Mac Mini (MB463LL/A). First thing I did was crack it open (Putty Knife, #1 Philips, T6 Torx, Strong Heart required), Upgraded the RAM to 4GB and HDD to 500GB. Loaded Vista, then later the Win 7 RC. I love this thing. I mostly use it as a companion to my game consoles (older games that aren't on consoles that i love). I plan, in the future, to install a few HDTV tuners, but with only USB availble to me, I might have to hold off on that, or find an alternitive. With FireWire 800, I also plan on adding a Drobo to expand on DVR capibilities. Once Windows 7 comes out, this is going to be the final OS I'm going to add. The Ir port is an apple protocol, but with my Harmony One remote, controlling Media Center is a snap. I wanted to setup my remote to act as a Media Center remote but the Ir port doesn't support that and it interferes w/ my Xbox 360. I already had a Logitech S510 Wireless Desktop Keyboard and a Logitech Media Click mouse, but i also use a DiNovo Mini keyboard with this.

I want to change the DVD drive to a Blu-Ray drive. but cost is holding me back at this time.

As for MacOS. I have it installed on a Thumb drive in case of emergencies. I used MacOS X 10.5 since it came out, but found it not right for what i wanted to use it for. Front Row is a joke and the lack of an intigrated option for DVR, that was a deal killer. Even thou a good number of my games that I play on this (Blizzard Titles) will work on this, Gametap isnt fully compatible.

Overall, Im satisfied with what I'm getting out of this device... just wish it was priced correctly and had a higher RAM ceiling. In the end, it might just become a Windows Home Server in conjuction with a Drobo or other external FireWire drive setup.