Rather than paper-printing supplements that cost money, why not have single-sheet scenario seeds that could be posted on a weekly or bi-weekly basis on this site?  I know the Dresdon RPG is going to be a FATE system publication, but if you look at the Savage World page (www.peginc.com) you'll find a number of single-sheet adventures for their system.  Most of them are for their 2nd ed. version of Deadlands, but lately they've been publishing some modern horror single-sheets as well.  These adventures are bare-bones scenarios with little more than a plot sketch and some stats for important NPCs and beasties -- enough game info for all but the most green GM.   

Basically, if you provide a "downloads" site for people to upload/download pdf adventures, I think it could do nothing but help the game.  I don't don't know of many GMs that couldn't bash together an adventure into a one- or two-page format without a little thought and effort.  I've written more than a few that could be easily bashed into the pretty much any game system (most are for Buffy or Savage Worlds, but its the story that's most important, not the system). 

The bottom line -- free is good, and if a bunch of us have already done the hard work, why not spread the wealth? 

Packy
A Dresden newbie, so don't flame me.  I'm kinda sensitive that way