I don't think we have much to fear..the warning was to install a patch that has been released some time ago already. Also if u keep ur antivirusprogram up to date ur most likely protected against it already.
Also handy is AVERT Stinger it scans for virusses/trojans/worms an related items...
get it here:
http://vil.nai.com/vil/stinger/
(it found a few items my AV didnt
)
Ohh yeah..what's sasser? It's a worm.