I think there is a niche market, yes. Just like there is a market for a paid twitter (app.net), there could be a market for paid for stackoverflow (just not something like experts-exchange).

I would call this "CTO for rent" or "tech lead by the hour"

note that there are many consulting companies that do exactly this, the thing is that they charge 100-200$ an hour.

I'm sure that in elance you can find someone willing to help for a nice reasonable fee.