Well, you're a step ahead of me. I'm still waiting for my HD & cable to arrive.
I know that the modem is hardware based, so it'll be able to run under Linux, thankfully. As far as the LCD goes, I'm not sure about the generic LCD working, since AFAIK, they all tend to have different max resolutions. The screen on my laptop will only run @ 800x600. There is support in the bios to stretch output to fit, in case something is running at a lower res. I think that the WP has something similar to this built in. I can't remember where, since I'm at work, and don't have my webplayer with me, but somewhere in the bois is a video options section. You can select different things, and I remember the default being set at "super". So it may have some kind of display stretching built in. But again, I don't know. :(
Which browser are you going to use? Hopefully not Mozilla. ;)
If there's anything I can do to help the effort along, let me know, and I'll jump right on it!