Donk, many flat panel TVs, especially LCDs, also have a VGA input. Take a look behind yours. If you have one, it will probably be labelled PC. You can just hook it up just like a computer monitor directly to the VGA output on your laptop.
Gibbleguts, I use a Logitech EX110 wireless KB/mouse. Works very well even with my equipment rack 15' behind the seating area.
I built a dedicated HTPC for our home theater. We currently have a 720p projector displaying on an 11' screen. (Yes, that's big.) I specifically chose a motherboard and CPU combo that is capable of displaying Blu-ray. We don't have Blu-ray yet, but when we upgrade the projector to 1080p, I'll be able to easily upgrade the computer as well.
If anyone's interested, here's the motherboard I chose:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131354
It has integrated everything, which allows the system to run cool and quiet. The onboard graphics are capable of running all but the very latest computer games. You ain't seen nothin' till you've played Bioshock at larger than life size.
Also, the amount of online video nowadays is very compelling. Between streaming HD Netflix, Hulu, and Miro I pretty much never watch television anymore. If I can just wean my daughter off Disney Channel, I'll drop DirectTV and start using the two HDTV tuners in the PC.