We have been rolling out internal instant messaging at the Big Green N for a few months now in a grass roots/guerilla technique. It has been a rousing success.
One of the major risks of using the publicly available tools (Yahoo, GTalk, MSN) is that all your corporate data is flowing over the public internet. Unencrypted and ready to be analyzed by the purveyors of those networks. Any reasonably company should realize that putting corporate data over an insecure public network is akin to letting competitors have a peek at your future product strategy.
This is not sensible.
When an organization has awareness of all avenues of communication their employees can use they can relax knowing that collaboration is still occurring, but within the rules defined by the organization. No public virus laden spam-bots sending messages, annoying your employees, while not denying the edge that instant messaging and presence notification provides.
One of the initiatives I have taken upon myself while under the N has been to roll out secure internal instant messaging. The major requirements of the system was for it to be open (as in standards), extensible (as in the programmable sense), architecturally compliant (Java & Oracle), scalable and finally - easy to administrate and use (less end user training and better cross-company adoption).
