The day has finally arrived, as the CyanogenMod team announced that 37 devices are receiving RC1 of CM9 today. This is a milestone, to be sure, as these builds should be more stable than any nightlies that have come before it. The issue tracker is also open now, so those of you that install this can report bugs and keep up on the progress of the fixes.
In the blog post, the team states that it took 225 days to get to this point since the release of Ice Cream Sandwich source code (and since work began), and because of the major changes Google made to Android they took the time to rework a ton of code for behind the scenes stuff. The changes they've made should make it easier to accept code changes and add new devices, because the "core" OS has been stabilized. Be sure to hit up your respective devices forums section to report back on your experience if you decide to flash this.