It's a no brainer for anyone looking to upgrade now, but only if they have very old systems. It's still not enough even over a core 2 quad or a phenom.
?? And what apps would those be??
For gamers, Anandtech reviews show 9 FPS over the X4 970 in Fallout 3, 26 in Left4Dead, 29 in FarCry2, 18 in Crysis Warhead, 44 in DAO, 28 in Dawn of War, 40 in WoW, 22 in Starcraft, 18 over the X4 975 in Civ V with full rendering and 44 with no rendering. And the 970/975 are not "very old systems".
For rendering/encoding/photoshop apps, the benefits are equally apparent.
To me it looks like Intel pulled off another Conroe - around 30% improvement over Nehalem, the prior gen.
I would wait a few more months, bulldozer could be special.
It could very well be, but my understanding is that AMD has optimized it for server applications...