El Reg (http://www.channelregister.co.uk/2007/12/21/dwindling_antivirus_protection/) is reporting that AV software is increasingly missing malware as the writers get more adroit at hiding their creations.
Encouragingly, though, "Eset's NOD32 detected 68 per cent of the completely unfamiliar attacks."
It's a shame the ESET suite seems to be giving some people problems (see Wilders). Installation issues and update problems seem to be the most common. I'm currently on Bit Defender, which updates hourly, and offers heuristic detection (as most do these days), but safe surfing is still the best way to avoid trouble. :)
Safe surfing is something a lot of people have no grasp of, Simon. Sadly, they are also likely to be the people with no AV. :(
I've used AVG for years and it's never let me down. It's scary to read that virus protection is getting worse. You'd expect it to go the other way!
It's a war, Sebby, and the battle will swing one way and the other - measure and counter-measure. In between, all we can do is dig a foxhole and be careful. :(