Yeah, Norton (and every other Symantec product) is garbage - far more trouble than it's worth, and not very effective either. Norton isn't very good at detecting trojans, and if the software goes wrong, it's a complete pig to remove and reinstall. I really don't like it at all, and I wish so many OEM computer suppliers wouldn't supply Norton on their machines - like old AOL software, Norton can be difficult for a novice user to completely remove, so they frequently end up stuck with this buggy & ineffective software on their machines.
The reviews in that article are certainly very biased- I can't believe that anyone who ran a serious test could possibly rate AVG's effectiveness as "excellent"!!

I was asked to fix a completely virus-infested PC a while ago, and tested AVG against PC-Cillin, running the AVG scan first. After AVG had "cleaned" the PC, I ran PC-Cillin, and it found a further half a dozen trojans & viruses that AVG had completely ignored (and these were not false positives either). Quite clearly, AVG isn't as efficient as PC-Cillin, so how they can rate both as "excellent" in effectiveness is beyond me. This is a pretty poor standard of testing, I would have to say - much like the pathetically biased "Which" reports, that they manage to con suckers into paying for, lol.
Regarding the Windows firewall, it is only suitable for running in an environment where attacks from other networked PCs wouldn't be expected (e.g. a home network) and a good SPI (stateful packet inspection) hardware firewall is also used (I favour Draytek routers, as their firewalls are excellent - Netgear etc just doesn't cut the mustard). In any other situation, the Windows firewall should only be considered useful as very basic protection, sufficient only until a more appropriate solution is installed.
I frequently build and install PCs for individuals, charities, and small businesses, and, for people who don't really understand the configuration of firewalls, with no likelihood of threat originating from their own LAN - i.e. the vast majority of end-users whom I support - the Windows firewall is sufficient. This is completely different scenario than a corporate or public sector LAN, where attacks from within the network should be expected and planned for.
If a wireless network is used, it cannot ever be completely secure - the new WPA2 standard can also be cracked reasonably easily. Bearing in mind that this security algorithm was designed by government workers etc rather than an open-source community project, it is inevitable that WPA2 can be compromised - it's not in TPTB's interests to design security that would lock themselves out too!
Common-sense when using a wireless LAN is never use wireless for any machine that contains, or has access to, sensitive or critical data. Instead, subnetting and firewalling should be used to keep the wireless LAN completely isolated from the wired. Trend-Micro's wireless intrusion detection can be useful - since wireless networks are inherently insecure by nature, I don't think it really makes any difference what firewall you use, so a simple warning that an unauthorised machine is trying to gain access is sufficient warning to switch off your wireless switch. The only totally secure wireless network is one which is turned off!
The whole anti-virus software thing is a bit of a scam anyway - any talented virus writer can expect to be snapped up and employed by one of the AV software houses, so the whole industry is designed to self-perpetuate.