I'm all for it.
I tried and tried to find a way to plan my setup using a mac, but it just wasn't realistic. Maybe if there was a dedicated forum, things would have been different (I doubt it though - at least in my case).
I already had a D-Link DSM-320RD (.avi format only) getting its stream from an old PC project that was in the closet;

TV just wasn't realistic when I bought it because of the price point and lack of DVD player which, in retrospect, I don't really need (now that I have HD storage space)... I also have a Wii that accepts streaming Flash video that's good enough quality for kid's shows, but it's now out of my daughter's room and back in the living room right next to the HTPC... Plus I wanted the ability to share files via iTunes on my MBP and iMac, so everything is stored in the PC's iTunes folder in iTunes-friendly formats. Right now, TVersity is the only program out there that converts on-the-fly from one format to another, and it's only for Windows.
In addition to being a HTPC, I wanted the machine to also be a reliable streaming media server. There's no way I could have built a Mac with HDMI out, 7.1 surround sound, gb ethernet, Core2 Quad (45nm), 2GB RAM, DVD burner, VFD with remote, and four 500GB hard drives in RAID5 for anywhere near what I paid for my DIY setup (about $650). And it still wouldn't stream to all my existing devices. And while the Thermaltake Mozart case may not be Apple sleek, it's far from a beige box.
In the future, I plan on just going with iPod Touches for each member of the family and a video out cable (or dock) attached to each TV for convenient streaming (or playing whatever is on board), no real-time video conversion needed. But the HTPC/media server would still be Windows (or Linux) based until used Mac Pro prices come way, way down (so I can gut one and stick it in the Mozart)...
Another option I started to consider was a Drobo as NAS and

Tv's on each TV set. But the setup would have come in at well over $1,200 for the Drobo, hard drives and 3

TV's. Simple, effective, but more than I wanted to spend.