I have to agree that linking up with Steam or somehow getting involved in the sales end of the gaming industry would make for possibly a good move on the part of the website as a business. Obviously, there is a ton of more money to be made if people are actually buying games,movies, audio etc.
As far as I know, there is not a Flash-dedicated publisher out there. If there is any website in the position to be able to become such an entity, then Newgrounds is that one ( with Armor Games maybe being second.) With all of the huge amount of popularity that some of these games alone receive, there have been plenty of self-sustaining studios that have come up out of this end of the great web of game-making talent. What there is missing, is a system to organize it all and bridge the gap between hobby and small-scale flash game makers, and the big professional-grade people. Steam serves as this for the general Executable-based gaming industry, but they do not deal in Flash games.
If Newgrounds could somehow become the Steam of Flash Games (Or collaborate with Steam to introduce Flash Games via Newgrounds into Steam, then I believe this would help both companies, the artists, programmers, animators etc that make the Flash products and the players like myself who would always love to have more gaming options available to us. Newgrounds already offers a working submission and hosting system so there would really not need to be anything new made on the inside design-wise. If what this site offers could be coupled with the (admittedly brilliant) sales tools found in Steam, I believe there would be a galactic-scale cash cow to be made.
Now I am not a businessman, programmer or anything like that, but I do know that, I would certainly be in huge support of a union like that. Just no matter what Tom, never let any company talk you into selling Newgrounds. Too many good sites have disappeared that way. 1UP is a major case in point, no matter what, don't let this place end up going the way of 1UP,please!