We looked at issues involved in getting RE onto valve here:
http://forum.freegamedev.net/viewtopic.php?f=72&t=3943&p=39986&hilit=valve#p39986 and essentially there didn't seem to be any big sticking points, the main things I wanted to make sure were:
The game could remain FOSS - yes
The game could still be distributed through other channels freely - yes
How much do valve take - 30%
Can the game be free, but you charge for extra content - yes
So a working business model would be do distribute the game free and charge for additional content. When Quin feels its time to get onto Steam then he should certainly talk with them about this, and show off all the goodies, and as you point out, show off the use of it by Illumiview (or whatever it is called). Teamxbow would be happy to provide the $100 whwnit's time.
To my mind the Steam Box coming out this opens up further opputunities, because there is'nt going to be that many games available intially even with Valves best effort at porting, so something like RE could be attractive, not just to the players but perhaps to Valve.