We've added and modified multiple rules in the chat, dns, exploit, ftp, imap, misc, netbios, oracle, policy, pop3, rpc, specific-threats sql, tftp, web-activex, web-client and web-misc rule sets.

Get it: http://www.snort.org/vrt/advisories/2010/09/27/vrt-rules-2010-09-27.html