Most users of this forum try to hide their identities. And I believe that ICQ, Skype, AOL or whatever other contacts are not used even by 0.5% of our users for communicating with each other, so don't see much sense for an additional server load.
Feel free to offer your Jabber server or an IRC chat for our forum users.
p.s. I use Jabber and SIP, as well as
Skype, MSN and ICQ.