following the link from jhawkkw will give you wifi and camera issues. been going through all the threads and a lot of people were giving their results. Apparently you will be able to flash back, but dont qoute me on that. Been reading so much today, that I have a headache.
Just read it up and understand what you are doing. Personally im going to wait, till theres an option that is 100% stable. Till then I use TiBu to freeze the necessary programs to stop the pop up asking me to upgrade.
People were saying that it will auto install after 15 mins, but I put my phone to sleep or pressed the back button on the phone, and it never auto installed.