Oh and some feature creep on top of that... it would help if i could work a daylight readable pedestal mounted weatherproof touchscreen monitor into the deal 
I agree wholeheartedly. Movies and on-demand content, however..Boooo! Tv Sucks!
Dude - the iMac thing is kind of brilliant, I must say. Sweet.Now I'm rocking an older dual-booted Imac with the stand cut off and mounted in the v-berth, so that I may blow my enemies into tiny bits (TF2 ftw) or curl up with Hulu while at the dock or via inverter in a pinch. I also picked up a netbook to do my casual work and surfing from the salon table, or to act as my chart plotter when I hook it up to the GPS. It works for me, but you may have grander ambitions. Good luck either way and let us know if you devise the perfect setup.