Battle.net hasn’t been upgraded much since it first came out. Blizzard have promised a new and improved version of Battle.net (2.0) that will coincide with the introduction of Starcraft 2 and Diablo 3.
Below is the confirmed feature list (source: DIII):
* Excellent Ping
* Channels and Chat in-game
* Ladders and Rankings, secured against cheating.
* Extended stats, with possibility to see who D/C etc
* AMM-type Matchmaking
* Avatars, Images and Icons to represent yourself
* Diablo III Hardcore mode
* Friends/Ignore Lists with advanced management
* Clan Support
* Automated Tournaments
In addition, there’s plenty of rumors regarding an Achievements system, Accountability (to track cheaters and those who use hacks) and Voice Over IP in-game chat.