I think that the biggest problem with the home theater PC is that in order to really control the system, you need to get behind a keyboard and have a mouse in your hand. I agree that more transparent control systems are going to be required. In addition, more manufacturers of powered loudspeaker systems need to begin to offer products that can cater to the sound quality requirements of home theater. If these two elements can get in place (one manufacturer, Canton, already has some self-powered hi-fi speakers), I think that the HTPC could replace the receiver as the central component in a home theater system.
I'm not sure if I like these mega-mergers happening in the industry. It seems like we're going to a one-board architecture, where the VPU and GPU are on one board, and once Intel purchases Nvidia, the user will have even less choice of what GPU to use.