I'm still holding out for the AirPort A/V. Maybe it's still too early, though. iTunes does trailers and videos, but I don't think that's compelling enough content. Streaming iMovies is nice, but I doubt an adoption driver. And then there's the whole composite, component, S-video, DVI, HDMI panopoly of connectors to deal with. But some day wireless video will happen.
Monster PMacs would be nice.
Otherwise my crystal ball is clouded.