I would take another look around, based on the little information that seems to be out there right now, Phenom II appears to be on par or slightly better then the 45nm quads from Intel clock for clock. Here is a good review. If you are gaming, it's fairly noticeable the GPUs are the main bottleneck now a days and the power of your CPU has essentially become irrelevent. A good basis to determine what setup is better is by looking at the CPU processing power for the video encoding benchmarks. That being said, I'm waiting to reserve my final thoughts once more reliable sites review the CPU.
CPU test Phenom II @ 3GHz performs around a C2Q @ 2.66GHz. Not bad but not really impressive either.
As far as what is better, AMD or Intel, I think AMD has the better price/performance ratio assuming my above statement is correct, but I think whether or not i7 is better and worth the price difference comes down to whether or not you need the additional raw processing power and whether or not you value the flexibility of using SLI or crossfire on the same board. Lastly, if you are getting a i7 build, be sure to get a tri-channel memory kit. The grand majority of dual channel DDR3 kits have a voltage rating that is too high for i7 (it shouldn't exceed 1.65V).
I saw a couple more benchmark sites and its dependent upon the site I guess as some are more for amd some are more for Intel. I want to see some legit sites also as you have stated.
You are correct about the Tri Channel kit and also so you will get the SLIGHTLY added performance increase.
Depending on what socket 1366 mobo you buy some have 6, some have 4, some have 3 slots for memory, you will have to buy the tri channel kit then put them into the appropriate slots or channels to get the TRUE Tri-Channel feature. Just look in your mobo's manual if you only get 1 tri channel kit, if you get 2 tri channel kits for a mobo with 6 memory slots then you do not need to worry.
IMO I would go for the Corei7 like I said to begin with but if you want to save a little cash go the phenom II way and with the $200 you might save put that towards a faster video card as I always try and get the fastest video card I can afford if I will be gaming a lot. The GPU is more important than the CPU as he stated as long as the cpu is fairly high end which both of these are not to worry lol.
The phenom II's may be the best price/performance ratio but for $250 more you can get the better system that is Slightly faster. Will you really notice the difference between the 2 systems, NO probably not. If I had the money and not watch every single penny I spend I would go with the Corei7 all day long.
It varies on person to person.
Either will be a nice setup so you can be sure both will make you happy. YOU decided on what you want / need.