I'm not sure what the version is or anything to be honest, but I received an email from noreply@updates.blackberry.com regarding the Bold and an update being available. Here's a copy of the email:
BlackBerry Software Update
Notification Update Today! ---------------------------------------------------- What else can your BlackBerry® smartphone do for you? Find out when you update to the latest smartphone software! This free update is ready and waiting to help you do more with your BlackBerry smartphone. To update today visit http://www.blackberry.com/updates New ways to work and play! * An update of BlackBerry® Device Software version 4.6 is available. This update includes optimizations and enhancements approved by your wireless service provider. Note: If your device is associated with an email account that uses a BlackBerry® Enterprise Server, contact your administrator for more information about updating.. Get the most advanced BlackBerry Device Software to keep your BlackBerry smartphone performing at its best. To update now visit http://www.blackberry.com/updates Recently changed your BlackBerry smartphone? If you are viewing this message from your BlackBerry browser, you can automatically update your device information when you visit https://ufs.websl.blackberry.com/ufs/update.jsp?hash=549654909B85543E29D80326D9AAF355B9 1407C4F474C76A773C84607A38EDD8E1FA3EAAC308800EAA6B D13B49D487281A5DE763ADDE1A4B4AD5687D76F99E001D4241 92C27367F455022C05678C6CD28D0980EB646B4614A8ECDC5B 0348EE417F65A. Research In Motion ----------------------------------------------------
It seems that it might be available OTA but I'm using the Curve right now so I can't try.

Cliff-notes: AT&T released a new OS today.