I'm not known for my naive, tongue-in-cheek answers, but I rely on industry and enthusiast publications for "the skinny" just like everyone else does.
A recent issue of CPU Power User Magazine for January, '08, has a series of articles that would answer your question completely:
Page 58 Phenom Explained
Page 62 The Power of Penryn
Page 66 Multi-Core Slugfest
and page 70 has an evaluation of several DDR3 modules and kits.
The upshot of it is this. Phenom may poise AMD for its big come-back, but it isn't, by itself, the big come-back. The benchmark scores from the QX9650 just blow away the Phenom 9700's scores.
Here's a few samples from CPU's page 68:
SiSoft Sandra Drystone: QX9650 = 58,221 Phenom9700 = 36,743
Whetstone: QX9650= 45,949 Phenom = 31,032
Floating Point x4 iSSE2 (fitps) QX9650=190,270 Phenom = 120,716
RAM Bandwidth Int'ger iSSE2 MB/s QX9650= 9,329 Phenom = 5,759
RAM Bandwidth Float iSSE2 MB/s QX9650= 9,299 Phenom = 5,773
Futuremark PCMark05 CPU QX9650= 10,148 Phenom = 6,713
3DMark06 overall QX9650= 17,471 Phenom = 13,731
Sony Vegas (min:sec) QX9650= 2:53 Phenom = 4:19
Price-wise, the 9700 costs less than a third of the Penryn. But in consideration of the Kentsfield processors now available, and the fact that even a mild over-clock to a Q6600 can take you to the same level provided by the QX9650 at its stock speed although the Q6600 has only 2/3rds of the Penryn's L2 cache, the answer seems pretty obvious.