I'm running stock 2.3.4 on my N1. And use Netflix all the time. If I were to load a different ROM like Cyanogen there isn't any reason I would lose the ability to use Netflix would I?
I use netflix on my Samsung Galaxy S Vibrant with CyanogenMod 7 and it works just fine. Now, that doesn't mean in the future, nextflix couldn't update their app to not support these devices/ROM but it does work now.