Vitalik tweeted there will be no rollback. As the hacker has only 3% of all ETH. A lot to be sure, but not enough to warrant another split.
It's also not really his fault either.. It's kind of up to the application developer to secure his users funds. Bad coding on his part. Has nothing to do with the Ethereum code from what I can tell. If you want to blame anyone, blame the wallet developer or yourself for putting your coins on there and just hoping.