Hows it going for Apple? Well according to Mixpanel they are over the 60% adoption rate. I suspect the glitch with 8.0.1 will slow it down a fraction but not noticably.
Starting around 08:00 on Weds 18th Sept iOS7 uptake was about 2.7%. By today, Saturday 21st at around 03:00 iOS7 and iOS6 crossed over and 7 rose above 50% Wow. Figures from Mixpanel