I also have the 2008ish Unibody MacBook. I upgraded a few months ago from 4GB of RAM to 8GB. It was well worth the upgrade. I have been reading many people with Office 2011 and Adobe CS 5 problems. I really don't want to risk loosing my projects if I can prevent it. Eventually I will go ahead and upgrade, but it does make you think how apple and developers can give you a run for your money requiring upgrades just to purchase their software. I'd understand if Snow Leopard was aged like Windows XP is today, but it was just a mere 3 months since Lion was released. ok enough ranting.

OP - good luck with your decision.