Lately, the small form factor market has gotten to be a little stale. For the most part, the "enthusiast" labelled SFFs are still small cubes. Sure, there have been improvements, notably the addition of AGP slots, and improvements to motherboard hardware, but not much has been changed to the basic model.
MSI, long time motherboard and video card manufacturer, has upped the ante somewhat with their MSI Entertainment and Gaming (MEGA 651) PC. Like other popular SFFs, the MEGA 651 is still "cube" in appearance, and offers support for fast CPUs and an AGP slot, but it has some unique ideas that target those specifically looking into building a Home Theater PC (HTPC).
Check out the review at
ViperLair.com