What a quad-core tablet means goes beyond just speed. Asus' Transformer 2 also has a docking station that allows the tablet to become a laptop like workstation. So far, we've only see something similar with Motorola's Atrix and Bionic.
I consider these docks to be important differentiators from Android competitors, specifically the iPad. And with Android tablets moving to quad-core chips so quickly, it could be a hit with the mobile crowd that are interested in specs above all else.
After all, I've already declared Android to be PC-free. And the success of Android tablets will only move that forward.