I said "AM2+" not AM2. A decent AM2+ motherboard can EASILY clock up a phenom. Just take a look at the AM2+ DFI 790FX motherboard. Also, there are no reasons for the 45nm chips and AM3 chips not to clock up high on the current AM2+ boards as they all have the same pin count/features besides a few architectures changes. I have also not seen any proof of the Intel boards below P35 clocking up Intel quad cores worth a damn.
I brought up AM2 boards as a counter to your argument that Intel boards before P35 aren't quad core compatible and there are a ton of AM2 Phenom compatible boards which isn't true. I disputed that and you added the "requirement" of decent quad core overclocking as a qualifier of your statement. The P965 boards don't overclock as well as P35 or X38 boards (or P45/X48 series chipsets do) however they still offer enough overclockability in the front side bus to allow for clocks that are most likely beyond what most chips can handle. In contrast no AM2+ board I've seen overclocks Phenom's via FSB adjustments worth a DAMN. Unless you classify a 50MHz FSB increase impressive. There are a few individuals out there that have achieved better results but they are extremely rare. If you want to overclock a Phenom you buy a Black Edition Phenom processor. This almost completely removes the board from the equation as you adjust their clock speed via multiplier adjustments almost exclusively. (At least if you want decent results.)
Since 45nm and AM3 processors aren't out yet you are only spouting conjecture and no hard facts. We don't know what a die shrink and DDR3 support will actually bring to the K10 architecture.