RTCOM (real time communications) subsystem in Maemo 5 is built on top of Telepathy. Telepathy plugins allow to set up any additional messaging protocols. For example, in Extras-testing there is now telepathy-haze which uses libpurple to support multiple messaging protocols. There is also telepathy-butterfly which supports MSN protocol directly.

Testing that they work might take some time but once people would verify telepathy-haze/telepathy-butterfly, they can vote for their promotion to Extras repository. After that they would be visible to a normal setup, without need to add Extras-testing.

For example, if I do following:
there will be MSN account type in VoIP/Chat accounts setup. I do not have any MSN account to verify that it works, actually.

When telepathy-haze and account-plugin-haze are installed, I also get 'MSN (Haze)' account type so now there are two ways to get MSN working.

telepathy-haze also gives ability to setup access to IBM's Sametime servers through wonderful meanwhile library.