True, and not true, all at the same time. The 3700+ would beat a Pentium 4 3.7 in games with a smile, but for video encoding, the P4 3.7 would tear the Athlon 3700+ a new one. It all depends on what you plan to do with it. But if you take an average between those two fields, they would be equal.
Why do they care? They don't, otherwise AMD would have tried increasing clockspeeds a long time ago. Its not about clockspeeds anymore, its about architecture. The same with the Conroe (from Intel), where the 2.6GHz model beats the FX60 from AMD. They basically built a CPU with a more streamlined way of doing things. That beats raw speed anyday!
AMD64 X2 4400+
DFI Lanparty Ultra-D
2GB Kingston Hyper-X (2-3-2-6)
TT Big Typhoon
eVGA 7900GT KO Superclocked (650/1650)
250GB Maxtor DiamondMax SATA2 HDD
Hiper Type-R 580W SLi PSU
19" Sony Trinitron CRT