I would say no. If the program uses the extra cores it will go faster. But It would not be enough to sway me to switch from a older potent system with the q9550. Even more so with the i7 due to needing a new board/chip/ram. At least with the amd you could still use your ddr2. It just dont sound worth it to me.
Maybe if you where doing HD ripping and encoding which takes alot longer then standard dvds to avi.