Also available on iPad! Haven't used my laptop since I read this and was thinking of doing the upgrade when I was surprised with a pop up msg on my iPad 1 telling me an upgrade was available! Clicked ok to install and after a few minutes I'm now running what appears to be a much more stable iOS beta!
That 30mb restriction was put in place by apple, however it is there to help the traffic of data flow as smoothly as possible, which is what At&T wants. If people were allowed to download how much data they wanted at a time, then At&T's network would be slower than it already is. But I really hope some of that changes with their acquisition of T-Mobile.