I am running a whole house DVR with multiple mini-Itx WMCs on Windows 7. I use Netflix, Hulu, my personal movie library, the Sports aggregator, HDHomerun Prime, Live Premium TV, Blu-ray, etc... I save over $40 a month from Comcast because I own my own equipment and I have a better DVR system than Comcast.
In my opinion WMC is certainly alive and it is the most overlooked Media Center. I have tried other systems XBMC, MythTV, Boxee, Hulu, Plex since 2005 and I have ended up with WMC and I will never go back. I'm no Microsoft fan and this is the one piece of Microsoft software that I am happy with.
I've done a ton of research on Media Centers and implemented a bunch on Ubuntu, Mac and Windows. I'm a huge XBMC fan but was mystified as to why the XBMC live television support was sub par. In 2011 I moved to WMC after I got past the denial that it was built by Microsoft. The DVRs instantly received instance wife acceptance and I haven't looked back since.