I'm leaning towards singles only right now, too. Doubles is a time sink at locals, everyone knows it. We can expand the singles tourney to include a play-in, like Dan suggested awhile ago, and I think that would benefit way more people than just running another same old doubles event.
Consider this tourney schedule:
12pm Melee Singles Pools
-- Melee Singles Play-In
3pm Melee Singles Bracket
6pm Brawl Singles Pools
-- Brawl Singles Play-In
9pm Brawl Singles Bracket
For people who forgot about what the Play-In means:
With an example 32-player turnout, you do eight pools of four and have the 3rd and 4th seeds (16 players total) play against each other for the last eight spots in a 24-player bracket. This gives more playing time to the lower seeds who usually tend to go two-and-out in bracket, and additionally gives them more playing time vs opponents of a similar skill level.
A less obvious example is something like a 20-player turnout. In that case you do the same thing except with four pools of five, making the 3rd/4th/5th seeds (12 players total) play against each other for the last four spots in a 12-player bracket.