While MSN Messenger 7.5 just came out, 8.0 is already being worked on and heading towards beta by the end of the year. Here's a list of possible and rumored features Microsoft is contemplating on going into the IM client:
? Change of Messenger Skins
? Real-time Emotions
? Messenger Built Internal Windows Media Player 10
? Pause/Resumed File Transfers (File Blocked Extension Applied)
? Detailed File Transfer (Download/Upload Speed)
? Animated Display Pictures (.gif .jpg .png (File Support under Consideration))
? Mood Status
..... (the rest at the source)

Source: TheHotfix