i talked to the bb techs at at&t.(spent 35 min.) they found some small problems with the meshing between their system and the new 4.5 os. they told me they are working the bugs out and will be available soon. as you can guess i am with at&t. this is just an fyi for at&t users.
I just downloaded the upgrade. After downloading the App Loader launched and searched for any updates. I got this message: "Your BB device is running the latest available software." I have 188.8.131.52..... I guess a little more patience from us!