List of features I'm hoping this has (in order of personal importance). This is all, of course, assuming it acts as a full media center extender (IE, just like XB360; live TV, MediaBrowser interface, etc)
1) Media compatibility as good as MPC-HC (basically, can play anything you throw at it). Including full res MKVs with HD audio (BD rips)!
2) Instant boot (<5 sec from on button until MCE interface is up, this may require a constant connection to the host box, that's fine by me).
3) No fans
4) RF and IR capable (I hate IR remotes, but, for legacy sake, it should have both)
5) Ability to use standard commercial skipping applications
If it has all these features, I'd pay 500/ea and take 4 of them tomorrow.
MediaCenter+Ceton+MediaBrowser is the most drool worthy setup that money can buy today (well, maybe some of the custom CE stuff is on par, but it's 100X the cost and not nearly as flexible). Everyone (and I really mean that) who sees my setup has their jaw hit the floor; "how can I get this", "how much does this cost".. The answer is "you can't, because you need a full time tech support guy" and "not very much". Not too answers that customers like to hear put together in one sentence.
This will go a LONG way to making 7MC a real "consumer" application. If this thing can play any content and all you really have to do it setup 7MC and point it at files, almost anybody could do it. The disaster with HTPCs is always codecs. Same with XB360s. PCH media compatibility with 7MC would be a really, really big deal.