It's not having what you want, it's wanting what you've got..
I have a Late 2007 BlackBook (2.2GHz, Santa Rosa, GMA X3100) that I bought as a refurb at a pretty steep discount on the day the Early 2008 MacBooks came out.
I was extremely happy with this from a price/performance/size perspective when I got it and that hasn't changed one bit. The only changes since then were to upgrade the memory from 2GB to 4GB and a 320GB 7200rpm hard drive (about $120 total from NewEgg).
The main thing is that it still does everything today that it did on the day I bought it. 😀 It's easy to get caught up in chasing the new features, cases, etc. but the use I get out of this on a regular basis (used as both a laptop on-the-go and a desktop in clamshell-mode at home) has been fantastic. I could sell this today for around $300 less than I bought it for almost a year-and-a-half ago, in part because there is still demand for the black MacBooks (and it doesn't hurt that it's in really great shape). To me, that is real value.
If I do anything else, it'd be to add a mini as a second "desktop" at home so I can use my BlackBook on the sofa while my son plays games, listens to music, surfs the web, etc.