...which would be nice if it told you anything at all about how people use their PC's in relation to their entertainment center, but sadly... no such luck.
Increased sales can be very much tied to falling prices and rebranding (the lowest-level entry on Dell's website is now $599 and is the next cheapest line to the I'M CHEAP CRAP(TM) one. But how much is the first model to come with an actual TV tuner and remote control on the base unit? $1200+ It is, in fact, the highest-priced base model in the highest-priced line of "Media Center PC's" (which are named that for merit of having that OS installed, but not much more.) For HP it starts at ~$800, so at least they're drawing more attention to it.
Since MCPC's failed at being "premium" computers, they've basically shifted down to the commodity end. Home is the base OS on the cheapest models, and Media Center has shifted down instead, as at least it's more marketable and makes people think they're getting much more.
So while they may move, they are still just going to be "computers" with more emphasis on integrated picture-viewing, etc. Just where and when and how much will be making the leap to "home media control center" and how well will it handle said duties, and will people be buying them specifically for that purpose? ...or will they instead be people's new computers with features no one things of using...? (Notice: the exact same complaint parallel people seem to have regarding HD DVDs?)
Personally, I still think we're a long way before MCPC's get any kind of living-room recognition. They still aren't being designed for it, they can in no way compete price-wise with current DVRs--especially since they'll be pushed and subsidized by the cable/satellite companies directly more and more--and "customer habit" is hard to break when it doesn't NEED to be broken. In regards to PC's in general, their use will come from "more networking," which I think it going to be the form of convergence this next generation will take. ...and the people who will drive things the furthest will be those who figure out how to make everything inter-operate the least-painfully for the consumer.