While the SEC measure will prohibit small investors from profiting on the downturn, big investors have a very easy way around this.
They will simply go short on complete indexes like the Dow Top 30, FTSE 100 or S&P 500 and will then go long, i.e. buy, all single stocks in that index that are not the ones they want to target. The net effect is a short position on the targeted financials only.
It will take a day or two for large hedge funds to set this up effectively and reprogram their computers to automate the process. Then the financial stocks will sink again as is appropriate.
Small players can buy inverse financial ETFs, like the SKF and puts on financials as well (assuming the ban on shorting by option market makers is lifted, which it should be)