It looks like Research in Motion has updated Yahoo! Instant Messenger for BlackBerry along with the recent updates to Google Talk and MSN Messenger.
YIM for BlackBerry is now up to version 2.1.33. There is no change log to speak and I don’t use YIM so I can’t tell you what changes have been made.
You can download Yahoo! Instant Messenger for BlackBerry here, so, if you are a user and notice something different, tell us about it in the comments.