For many 11.10 is already on their machine(s), but today was the day to being installing and upgrading. So far the process was smooth as silk. I reinstalled on my work laptop (Lenovo W520), home laptop (T500), home desktop (self-built using DP965LT mainboard and Nvidia 8800GTS graphics card). My daughters desktop (self-built D865GRH mainboard with Nvidia 6800 graphics) is currently processing an upgrade. No gotchas, not a single issue with the install process. I still have three servers at work, one more laptop and one more desktop to go.
I have to say that Unity is looking more polished and is more pleasant to use. Overall I am impressed with the work done on Oneiric. Congratulations to the Ubuntu developers and Thank you.