I am now running 4.5.0.138 on my ESN 8330
Their is no file to download yet!
Seems you will need .131 installed on your BB and on your PC go to C:\Program Files\Common Files\Research In Motion\AppLoader and then for the vendor.XML file should be deleted or edit it to read <vendorsrc version="0.0.0.0">
Next (with your BB pluged into your PC but DM not running) go to
www.balckberry.com/update install the active X control and it will then launch your loader.exe app (it may update it to 4.7.0.55 first) and it should show you the 4.5.0.138 update.
I have confirmation form four people now and its not carrier specific.