According to Microsoft, massively multicore CPUs need massively multicore aware software and tools, or you wind up with something that does not go very far, Microsoft has said. Seemingly, single threaded software is going to benefit poorly from multicore. Things are not so bad on the server side, which will benefit, but desktop users are going to have to use specially written code to see benefit.
On the server side, no problem. If you have 1000 people hitting your web server and can dedicate a core to each, things will positively fly. If you have a game that has a single critical thread, you are going to get some pretty lame frames d00d.