I am unfortunately not as optimistic as you; I think Nov 4 will result in a humiliating loss for McCain. I think it will be akin to Carter's and Mondale's losses to Reagan.
I also think we will see alot of seats in congress picked up by democrats. On top of that we could potentially see a couple of conservative Supreme Court Justices replaced in the next two terms which is truly frightening to think that all three branches of our government could be controlled by liberal democrats.

Back to the topic, I think we will see at the a new AWB, probably one worded like the one they tried this last year. Don't be surprised if there is legislation passed that requires the registration of all firearms. People on these boards seem to frequently talk about hiding firearms or claiming they were all lost/stolen/sold/etc. That won't be as viable an option if possessing an unregistered firearm is now a felony or federal offense. If you were to get caught with one, say at a firing range, which would perhaps be required to check serial numbers of all firearms, you would then lose the right to have any firearms whatsoever. Once they have them all registered, they can then pass legislation that will say possession of prohibited firearms (assault weapons, for now) is a felony. Then they can make you turn in banned weapons.
I do not expect to be able to buy or maybe even own a semi-automatic rifle one year from now.
A couple of other things I expect to see happen next year is a federal mandate for the repeal of all carry laws. If I had to guess, I would say this will be done through withholding federal funds for something, probably law enforcement, for states that do not comply (much like with the federal .08 BAC mandate).
Another thing that we may see is a huge cost increase in ammunition due to obscene taxation and requiring technology like this: (http://technology.newscientist.com/article/dn14454-pollencoated-bullet-could-make-its-mark-on-criminals.html)
which will add a HUGE expense to the manufacture of ammunition.

The AWB will pretty much negate the second amendment, but that didn't stop it last time. I would not expect it to have the "loop-holes" in it like the last one. I see no reason for them to put an expiration date on it, or allow people to keep previously owned banned weapons. I expect "assault weapons" to be classified and regulated just like machine guns.

Of course this is pretty much the worst case scenario (at least in the near future), but I am really afraid this election absolutely can and will result in the worst case possible as far as gun rights and the second amendment are concerned. I also think this stuff will get pushed through congress rather quickly. If there are enough dems in the congress and senate, they can override any kind of filibuster and send it to a vote, which will have no problem passing if they have enough of a majority.

Please someone correct me if I'm wrong, as I don't know as much about the process (passing legislation - especially unconstitutional laws) as I should. This has really been bugging me for a while and I think I'm going to buy a rifle which I cannot afford right now, because I don't think we'll be able to in a few months. I just hope I don't spend $1500 on a gun that is just going to be confiscated next year.

As you can probably tell I'm a little pessimistic, but as far as I'm concerned, things don't look real good.
I hope to God I'm wrong.