Existing short positions are grandfathered.
Right now, you may not short to hedge options. As a result options have started becoming more expensive (spreads widening). The option market may seize up next week. The SEC may grant an exemption for option market makers (link) but it certainly opens the door to abuse of the rule.
The Short financials ETF (SKF) was halted shortly after it opened for trading on Friday. Trading resumed, but no new shares will be created. I expect it to go up because now it is the only way to short financials and supply is limited. (link)
Credit Default Swaps (the white elephant in the room) are still completely unregulated. The SEC has no plans to address them.