Yeah it'll take 2 quad cores, though having 8 cores seems utterly pointless at the moment for anything other than specialist uses.
Penryn is a bit more than a mere die shrink, apparently it'll be 10% faster than Conroe cores clock for clock (with Conroe being something like 20% faster than A64).
The big question is whether it also overclocks further than the Conroe. A die shrink suggests that there's no reason why not, but at the same time AMDs die shrink to 65nm did nothing for the overclockability of their chips. Making clock per clock improvements as well may indicate that they won't overclock as well, due squeezing in more performace per clock and leaving less slack for higher clock rates.
Jokester