Haven't seen it suggested, and it may be included in any future chat upgrades, but...
Please let us see if our friends are online even if they are not on the same server. Having to log out, and check the (buggy) server list for friends online is not ideal.
Additionally, inter-server PMs would be nice to chat with said friends.
Other things could also follow, such as a new 'Global' Chat that is inter-server.