Yeah but Intel will have Ivy Bridge out early next year so AMD will fall behind again.
http://www.techeye.net/chips/intels-ivy-bridge-will-rule-the-chip-roost
Ivy bridge will still be quad core, and will have an IGP taking up space and(for most enthusiasts on here) be a bit of a waste of space, less so if they can get quicksync working with discrete gpu's as people do transcode stuff, though I don't, feels daft buying something I won't use 1/4-1/5th of.
Its quite likely a 8 core BD will both spank a Sandybridge silly, and get spanked by a octo core i7 sandybridge E, but you're talking about £15-250 chips vs £500-1000 chips on £200-400 mobo's so I really couldn't give a crap about that.
In the mainstream/enthusiast sector(excluding stupid rich people) Intel will have £150-250 quad cores against AMD's octo core up till seemingly around the end of 2012 which isn't exactly soon.
Some benchmarks are going to make the SB look slow at the same price, some will be close, I really don't think(quicksync transcoding aside unless BD has a BIG surprise) that AMD will be competitive in transcoding, hardware decode beats software, hands down. WHere SB gets beat, I don't see Ivy being a huge improvement.
Intel don't need, but SHOULD have a octo core in mainstream by now. Q6600, 65nm launched Q1 07, 4 years later, still on quad cores and they won't do mainstream octo cores till almost 6 years later.
Somewhat think AMD have made the right move, bring APU ti mid/low end where price/die size/power/efficiency are key, go for octo core, and intergrate a GPU next gen. Who is really buying a 2500k/2600k for a gpu? At the very least they could have gone with the same die size and 6 cores.