The house and senate are so divided that nothing of substance is likely to happen, and NOTHING will happen quickly. They can't even agree on the basics of handling a trillion dollar "fiscal cliff" problem.
Prices are high right now on AR-15s in particular, but all semi-auto rifles chambered in 5.56 or 308 or 7.62x39 are inflated. If you need the cash, now would be a good time to sell, but why not hold on to them? honestly... It might be more difficult to buy them in the future... more hoops to jump through, more PITA paperwork or whatever.
My advice is don't over react. Some people are being foolish and paying huge amounts of money for 30 round mags. But selling a gun you would otherwise keep is just as foolish...