I'm still trying to puzzle out what to do with my MacBook Pro. It is the early 2008 "Penryn" with a 2.4GHz processor. It needs a new battery, some extra RAM, and a larger hard drive, to be really useful to me in the next year or so. Those will cost about $300-$400. Or I could sell it and buy a new one. The price to upgrade after selling my current laptop would be about $1200-$1400, depending on the configuration. I'd upgrade to the same 15inch screen I'm using now, so it would be a 2.6 or 2.8GHz processor. Based on the initial numbers, it seems obvious that I'd be better off upgrading, but I am not completely sure. First, if I wait a year or so, the resale value of my MBP, currently estimated at $950, plummets. Second, I don't really know the lifespan of my laptop -- I've been pretty rough on it and dragged it around the world more than a few times. So if I can get a good value for it I might want to trade up before it becomes obsolete and/or craps out on me. The alternative philosophy is to just invest some money on upgrades and hope that it lasts me another 2 years. My luck with laptops after the 2 year mark has so far not been great, hence my worry. The most processor-intensive thing I use it for is loading raw photos which I process in Lightroom. I also will be using it to run Parallels & Windows 7, but not doing anything very power-hungry on the Windows side. And yes, yes, I know ... wait for February to upgrade.