It all depends on what your phone is. Nexus One gets a firmware swissie in the shortest possible time directly from Google. HTC Desire, as his brother also gets them in a short time. With other devices more difficult, craftsmen harder to make an updated build, but they, nevertheless, there is. Most "multidevice" —
CyanogenMOD:
1. Nexus One
2. HTC Aria
3. HTC Dream / HTC Magic
4. Motorola Droid
5. HTC Desire
6. HTC Evo
7. HTC Slide
8. HTC Hero CDMA
9. HTC Hero GSM
10. Samsung Galaxy S
11. HTC Incredible
12. HTC Legend
It is collected from source posted by Google and the manufacturers. Often not working things like camera, FM radio, etc., because these things strongly tied to specific glands, but the rest of the firmware is quite stable.