I'd speculate that Iran isn't financing them, because I've never heard an allegation, they're Sunni, and they don't have a record of blowing up Israelis or Americans.
Not sure on the popularity thing. I'd say plurality support, off the cuff, based on recent history, but a big portion of that support is "anyone but Mubarak" moreso than "sharia law rules". All gut feelings on my part though.
I've been researching them a bit further and it definitely seems they would command a majority of the votes at the moment so I really have no idea why people are so quick to write them off.
Agreed on the 'anyone but Mubarak', if this thing does not blow over Mubarak will be a very lucky man if he manages to even reside in Egypt, if he is forced out and does not flee abroad in time he's as good as dead.
Ok, that's a good thing then.
Is Iran financing them? Or do they have local support?
What are the relative proportions supporting these factions in the population?