Negative
I recently upgraded from a 2.4ghz Aluminum MacBook to the MacBook Pro that I currently have. I use it mainly for audio production, but also for various other tasks, such as web browsing, listening to music, and a bit of Dj'ing. I have yet to, besides the odd video editing I do, come anywhere close to the limit of this computer. Even when running my audio production programs, Logic, Pro tools, Etc, I have never even come close to 50% CPU load according to iStat. I upgraded to 8gb's of ram, and will eventually get an ssd. I would have opted for the i7, but I found it to run a little to hot sometimes. With that being said, I wouldn't have even noticed the speed difference. Even as minimal as it already is.
So in short, no, I wont be upgrading. Not for at least 2-3 years.