I was upset when my N1 didn't get the Android 4 release. Apparently, the whole Nexus thing means you are first in line to get updates when they come out (as opposed to carrier phones which frequently get updates several months after they are released, and may never get updates), but that only lasts for about two years.
Although 3rd party developers eventually brought ICS (and Jelly Bean for that matter) to the Nexus One with a lot of hacking, there were good technical reasons why there was never an official release. ICS needed drastically more space on NAND than Gingerbread, as evidence by 3rd party ICS ROMs requiring you to repartition your NAND as well as mount /data on the SD card if you wanted to install more than two or three apps, which then led to greatly reduced I/O performance.
The Nexus One couldn't install ICS or JB because Google and HTC made the stupid decision to give the system only 256 MB of storage--relying instead on the "endless potential" of SD storage to store apps. <facepalm> I can wipe my Nexus One, return to a clean copy of Gingerbread and will still only have about 30 MB of space for apps. What a joke.
