The exact limitations on what one can due via Executive Order haven't been hashed out, but trying to flaunt a Supreme Court ruling and institute policies that aren't supported by the legislature would trigger intensive backlash from those two branches. Heck, it might be fun to see.
I agree, which is why it is so important to think about whom he would appoint to the Supreme Court. He will likely have at least two appointments in a second term, and possibly three. I believe Obama to be a patient politician when he needs to be. If he were to be elected to a second term, he may wait until he's able to appoint justices who are not so supportive of the Second Amendment, then go for EO's which tighten gun control laws. If the democrats keep the Senate and retake the House in 2012, along with an Obama win, that would present an even more dangerous situation for gun rights advocates. I think it will be hard for democrats to retake the house. I'm hoping they don't. We need conservatives to get out and vote, regardless of whether they like the GOP nominee or not. We need to have more pro gun rights people in congress, especially if Obama wins a second term.