Steve a few points:
1) Disagreeing is fine, that's how we all learn.
2) Linux is the title of this thread, and linux is used to run most of the satellite/cable HD source devices, including PVRs. Seems quite appropriate from this perspective to use linux as an OS for an htpc to me. A networked/integrated client/server system (say 3 clients and 2 servers) that has 6+ separate PVRs, offers an integrated menu system (MythTV) for controlling recorded and live MPEG2/MPEG4 video, DVD disc playing, recorded lossless audio (and lossy), picture database, integrated TV-Guide, weather forecasts, and web browsing sure seems like a pretty complete htpc solution to me, don't ya think ?
3) Sorry, not everybody is like you and needs the uber HD resolution of the day. Many will be able to use a 6150 based solution with what they have today and will be able add a higher performance PCIe video card later if need be. That fit's your defintion for future proofing doesn't it?
3) When you say "I've never found a built in graphics that will handle full HDTV streaming," you aren't really keeping things factual, you're just giving an opinion. It is well known on all the htpc forums that Intel has never had (still doesn't have) an onboard video solution that anybody could use for an htpc.
Frankly, I find your opinion a little too elitist, but that's OK because it's your opinion and NOT FACT.
nvidia 6150 and video card specs