"Is an instant messenger next for Google? Some say that Google has been planning this move for quite some time. In their Desktop search Google included the protocol handler: google_im://. Google gives the reasonable explanation that it is there for searches of you instant messenger conversations, and it is not there for some future IM software."
Far more likely that they are going to add support for the variousl IM logs created by IM applications or something. As far as the meetro application goes, it seems far more likely that this might be a push towards Googles plan for personalization. Search based on location and so forth. Something like Apples Bonjour and iChat for localized chat:
With the help of Bonjour, iChat AV lets you see which people are available for chatting or video conferencing on your local network, and automatically removes them when they leave.