It's interesting and sad that this is the way it is. I'd get way more benefit from another core than another GHz. I'm sure it's not just developers in this boat, but I too am pessimistic about the size of that market.
Would software developers change their approach to coding if 32-core chips started to show up in consumer machines? I'd like to think so, but then again, I figured everything would be multithreaded by now.