This news might not be exactly Adium related, but it is definetely IM related in general and so i think it is interesting for the Adium community anyway:
After the recent connection between Windows Live Messenger and Yahoo! Messenger Microsoft seems to be currently working on a similar bridge to the AIM and GTalk networks (Link).
According to one of Microsoft's devolpers there is already an early internal version of WLM 9.0 that offers basic GTalk integration while they are still trying to figure out how to connect to AIM (actually it's no surprise that the GTalk integration is the easier task since Google already offers open server-to-server connections).
Although the final version of WLM 9.0 is scheduled for late 2008 or early 2009 it seems the decade old barriers in the IM landscape are slowly begining to fall.
great news i think.