This is version 4.5.0.66 and appears to be the latest release. I haven't tried it yet, it's DL'ing now.

It is a release for US Cellular so don't forget to delete the Vendor XML file if USC is not your carrier. Here's the linky:

https://www.blackberry.com/Downloads...B58CE00D1194C9

If you are thinking about upgrading to this OS, but you aren't sure, then I suggest you go ahead and DL the file anyway. It can always be installed at a later date. You never know if it will disappear like 4.5.0.56 did when MTS pulled theirs off (see first post).