Sometime SSR doesn't get around to signitures for every piece of malware under the sun. They say that SONAR should stop active malware in its tracks. I have not tested SONAR extensively; and I would rather not resort to the last line of defense which supposedly missed an icqbot and a virtumonde infection. However, NIS09 did not get around to a full system scan when NOD32 and Panda's online scanners picked up those infections.
I would like the ability to create your own malware signatures within 2010. You could download malware for examanation, and once you are done, you can create malware signitures within 2010 and scan your computer for traces of that particular malware. Remember, you do not have to execute a file for it to infect your computer.