Face it, the Merom chip-powered Mac is a legend. A myth. It doesn't yet exist. If and when it happens, we will then know how powerful/hot/battery conserving/expensive/able to leap tall buildings it is. Not before.
If you want uninformed speculation, Search the forums for Merom, you'll find plenty.
Givens:
1) Apple will continue to release new machines based on the latest available technologies - and they will continue to not preannounce products before the launch dates
2) Apple will make product specification decisions that many people with disagree, argue about and second guess, ad nauseum. "They should have included (xx) in the machine, but kept it at the same price."
3) People who bought a machine within (1 - 2 - 4 - 8 - 16) weeks of the announcement will whinge and complain that it isn't fair that THEY bought a machine that is now obsolete.