Why can't users cast on-topic/off-topic votes on suggested questions once a site proposal has reached commitment phase? I'm assuming the rationale is that the definition phase is over, so you want the definition to be set in stone. I can understand that, but I'd suggest that you think about the way it comes across to the user who first gets involved during the commitment phase. For me, it was kind of a buzzkill. I found a proposal I would be interested in (Gaming), and followed it and committed to it, then I learn, basically, that I can't do anything else but refer other people until the site reaches enough critical mass to be created, whenever (or if ever) that happens. All I can really do is wait around for an e-mail.
I would be uncomfortable letting users continue to work on the accepted proposal once it is "done."
Users are committing to a proposal based on a series of questions shown to them when they digitally sign it. It doesn't feel proper to have that page change dynamically, after the fact. Even if you froze the Commitment questions, the actual top questions could be changing behind the scenes.
There aren't a lot of people visiting the Definition area during Commit. That lack of eyeballs creates a serious accountability issue if someone tries shenanigans while no one is looking.
It's time to move past work that is, essentially, done. Don't overengineer it. Go out and evangelize the site and get ready for the beta. You'll have more than enough time to contribute improvements during the real discussion... in beta.
I think that there should be voting on other issues such as the name of the site and whom the moderators should be during this commitment phase so that when the beta period does start, people would have already voted on this information that is necessary for the beta.
Update: I added this as a feature request here.
I hate the fact that by commitment phase it is too late to vote on changes to the name, description, or vote on on-topic / off-topic questions. It gives too much weight to the first contributors. For example I just committed to Compiler Design. The description is:
Compiler Design Proposed Q&A site for those wanting to discuss language design or create a compiler/interpreter using existing tools or from scratch.
I like the description, and I like the community, but the name is absolutely misleading. It should obviously be called "Programming language design and implementation". But it's too late for me to even petition. After clicking around for 10 minutes like an idiot, I see no way to have my voice heard. So I have to come here to complain. Not fun.