Not really. XP will always be vulnerable, and with the price and requirements of Vista, most people won't get it for a while yet.
Considering that almost all new computers ship with Vista, quite a few people will be getting it.
With regards to the OP's post, I think that XP became pretty secure when Service Pack 2 got installed. If you do the three things that it bugs you about, then you should be pretty good to go:
1. Turn on automatic updates
2. Install and update antivirus
3. Turn on firewall
Of course, upgrading to a safer browser, such as Firefox, Opera, or IE7 also helps your security. Also, practicing safe computing is important (e.g. don't download files from unknown sources and don't install every crappy piece of software that you come across online).