This post is no longer active, the latest data is available here.
After seeing how well the OTA 5.0.1 update had performed over the first couple of days, I was curious to see how things progressed after 10 days of data.
Here are the numbers through today:
Upgrade rate for 5.0.X devices only.
Upgrade rate across all OS versions.
Overall, things are looking really, really encouraging. I think we can finally expect rapid deprecation of old iOS versions.