The reading I get from the above, and from some other sources, is that the old AVG version (7.x) will no longer be supported. The new version (8.0) can be still obtained as a free program; but to encourage purchase of the full program they've made it a little more difficult to find the right button to download the free version.
While AVG remains one of the "reliable" AV programs, recent reviews have indicated it hasn't quite kept up with some of the other "free programs." That doesn't necessarily mean that it's not a good choice for most people - only that for this week and until the next reviews come out it's perhaps not the ultimate thing you can get right now. The various programs do "swap places" in the reviews pretty regularly.
I don't think you'll be hurt by having Norton 360. You should get "full support" if you happen to need it, and despite some clumsy web design and a pretty crude "help" site, I've found Norton sufficient and not unreasonably expensive for several years now. The Norton Internet Security retail packages we've gotten most recently allow use on up to three computers (for home users) for one payment, and $23/year per computer seems quite reasonable to me, to have someone I know I can call if I need help. Does Norton 360 (their current "flagship" program) offer the 3-machine license?
RB - I've noted some "different" behaviour in Ad-Aware SE (free version) with the latest update. For one thing, it seems to think my mudcat cookie needs to be deleted. I don't run it as a "real-time" thing, so it doesn't affect anything unless I initiate a scan. My Norton IS has good anti-spyware, anti-phishing, and all the other anties and unkies so I find AD-Aware useful only when "annoying but mostly harmless" crud builds up and needs cleaning.
Since some of the advanced help sites still request a run of Ad-Aware and Spybot S&D, before submitting a HiJack This log to request assistance, it's still a good idea to have all three on your machine, in case of dire emergency; but it's doubtful that any of the three actually adds much useful runtime protection if you have an up-to-date full-suite AV.
I haven't seen reports on whether AVG v8 slows anything down. Changes in the kinds of threats, and inclusion of protections against new kinds of stuff, have made most protection programs/suites somewhat "intrusive," but it's mostly a necessary evil if you want the expected levels of protection.