The Core2 line is certainly nice.
Finally a reason to even consider switching back to Intel. Of course, it took them long enough...
We'll see how AMD responds. Right now, comparing the Core2 to the AM2/S939 Athlon64s and Opterons is like comparing the Pentium 4 to the AthlonXP (new vs. old generation). Yes, the P4 whomped the AMD for a little while, but then...
For me, I already had a S939 nForce3 board sitting unused. I also have a still-got-some-legs-left ATI AIW X800XT video card (AGP) and 2 GB of nice DDR500 RAM in my existing nForce2 AthlonXP HTPC machine. Upgrading to the dual-core Opty was a perfect fit. I can keep using my existing stuff, and still get piles of new performance. Had I won the lottery or something and been able to upgrade from scratch to a brand new machine, I'd have had to strongly consider the Core2. But then, if I had that pile of money,
I'd have probably grabbed one of these and thrown Windows XP on it (mmmm.... dual-xeon goodness).
That's what I like about AMD. It seems like every new chip Intel releases requires new CPU, new chipset, new RAM, and every so often a new video card too! Upgrading a little at a time makes sure I can maximize the serviceable life of my components (and also lets me upgrade a "little at a time" rather than having to come up with a huge pile of money all at once).