MSN Messenger 7.5 is now released. Nobody seems to have noticed. I'm sure there is a bunch of new stuff, but all I've noticed so far is: 1. a new sign in screen. 2. voice clips (short audio clips you can send during an IM session. 3. dynamic / animated chat backgrounds backgrounds. There are some minor UI changes here and there.
Some have complained about the crazy amount of tabs that seem to grow with every version. I've found at least one way to turn them off: Tools, options, security, check "This is a shared computer so don't display my tabs."