The reason to stick with AMD is IMO not for AM2, but for socket 939 since being able to keep your RAM can save a couple hundred dollars if you've invested in top notch 2GB DDR.
For myself, I just got some Sempron 2800+ AM2 chips sitting here (waiting for RAM/mobo). Couldn't pass up the $36 price - damn the hot deals forum!
I personally would not buy any of the current Core 2 Duo CPUs - I'm waiting for a $130 C2D E4300. If someone wants to drop $330 for an E6600, that's their business and more power to them, but to suggest that EVERYONE NEEDS to drop that kind of money on a CPU is like saying EVERYONE NEEDS dual 7900GTX cards in SLI. If people are so sure that everyone needs it and life would be better with those more expensive components and buying them will increase the quality of my life, end starvation in 3rd world countries, make all terrorists drop dead and pot a stop to global warming, then dust of your wallet and give me some of your money so that I can buy the expensive stuff too, otherwise STFU!
That's not directed at anyone in this thread necessarily, just at the "other" times I've seen people go "OMG C2D FTW stupid to buy AMD now 'cause I'm a wealthy and elite bastard."