Probably the most requested feature for Wildfire and Spark is the ability to chat with users on the public proprietary IM networks: AIM, ICQ, MSN, and Yahoo (Google Talk already works great with Wildfire and Spark since it can federate through the open XMPP protocol).
I'm happy to announce that we've been working with Daniel Henninger on a new Open Source gateway plugin for Wildfire. Daniel has brought his experience working on the Python gateway components to create a very easy to use gateway system. At the moment, there's support for AIM, ICQ, MSN, and Yahoo, with IRC support coming soon. The code is still in the very early stages, but there's already some things that make these gateways different than what's been done before:
Installation and setup is trivial since it's a Wildfire plugin. Existing gateways for XMPP servers have to be installed as external components, which means installing dependencies, config file edits, etc. Also, working as a Wildfire plugin gives the gateways internal access to the server, which allows nice features like dynamic changes to users' rosters.
Web-based administration of the plugin allows each network to be enabled or disabled along with features and permissions, and to view and edit gateway registrations.
Tight integration with Spark: we're building extremely easy to use Gateway support into Spark. Of course, any other client with gateway support will work as well.
The current plan is to have beta releases available in the next several weeks. We'll also provide continued updates on development progress in the forums.