I just wanted to mention this for those who like to run virtualized operating systems and apps. There is another feature that only the 2.5GHz dual-core Mac mini (the one with the AMD Radeon 6630M dGPU) has and that's Intel's VT-d (Virtualization for direct hardware I/O). While I can understand that the low-end dual-core 2.3GHz might lack an advanced feature like VT-d, I was particularly disappointed to find out that the highest end mini, the 2.0GHz quad-core server, does not have this feature. Virtualization can be an integral part of a server, depending on its role. Obviously, for those people who could care less about virtualization, this is a moot point, but I do run Windows 7 via Parallels and with OS X Lion, you can, for the first time, run Lion within Lion. That's great for trying out beta software that you don't want to negatively affect your "main" OS X installation, for example. I do want to make one point, though: You can still run virtualized OS's, as I don't know about a single Sandy Bridge CPU that does not have the main virtualization feature called VT-x. I currently have the 2.5GHz Mac mini and I really like it. I love the fact that the optical drive is gone, but I'm still on the fence as to whether or not to upgrade to the quad-core mini for what are now TWO reasons.