One thing not mentioned explicitly in the rules: round length. Is there a round clock, and if so, what happens when it runs out?
Your local Dominion scene can put up ~25 players? Man, must be nice.
I usually do a cap of 45 minutes on each game -- if the game isn't over by that time, we play until everybody has had the same number of turns and then end the game there (unless the game ends naturally first). I should say that I haven't had this happen yet -- at one point I was about to call time and the game ended anyways. The idea is to have the Swiss rounds last until 5PM, then everyone who doesn't advance is dismissed at around the same time as people are coming in for the regular board game night (and at that point I'm not taking up so many tables).
This venue can comfortably hold 100 people, it's really nice to have this place around, since all of the other people I've talked to who have put IRL tournaments together tell me their biggest constraint is table space. It's nice to have different problems than them
Usually half of the store is taken up by MtG events anyways.
Another update: I can expand the capacity of the tournament to up to 35 people if needed. This takes pretty much all of the fear of being over capacity away. Looks like F.DS will be reasonably well-represented as well, I know of seven people from F.DS that plan on coming.
Don't you think 36 players might be better?
Of course this would be better, but the thing constraining how big the tournament can be at this point is the number of supply card sets I have access to (Province, Duchy, Estate, Curse, Copper, Silver, Gold). I have 11 of these sets available (9 games of 3 players and 2 games of 4 players, that's where the number 35 comes from), this is the most I can do within the format. My guess is we'll have 20-30 people there, and I'd be really surprised if we went above 35 so I'm not planning for any more than that to show up.
If the tournaments got bigger, of course I could buy more sets of the Base cards. They're not prohibitively expensive, but I don't have a need to do that at this point. I can't wait for the day where the competitive Dominion scene has grown so much that I need more base card sets, I hope that's my next tournament (it's a 2P tournament, which requires more base card sets for the same number of people).