It will make it possible
* To not try to remember difficult commands. Even a newbie will be able to chat in IRC.
* For the client to be able to understand what services want.
* For the client to be able to show all services messages in locale-specific language.
* For the client to be allowed to create useful scripts, such as a password manager.
* Secure MD5 auth will protect your password even over SSL-disabled connection
* It is backward-compatible. All old clients will be able to continue with services as usual.