Google Talk is down at the moment!
Google has confirmed through the Google Apps Dashboard that Google Talk is currently facing stability issues.
I have been facing connecting my regular Gmail and Google Apps accounts for about an hour now.
Google has this update:
We’re aware of a problem with Google Talk affecting a majority of users. The affected users are able to access Google Talk, but are seeing error messages and/or other unexpected behavior. We will provide an update by 7/26/12 5:20 PM detailing when we expect to resolve the problem. Please note that this resolution time is an estimate and may change.