Some experts in computer science security believe that they have discovered in the code of the latest "Google Desktop" app, indications that Google is developing a tool of IM. The speculation, that is not new, has gained points after the announcement of "Google Desktop.

After looking at the code of this application, Richard Smith, a popular consultant of security, it declares to have found in his interior references to a new protocol: "google_im://", destined to interact with the navigator of Internet, and that according to the first indications could correspond to "Google Instant Messenger". Smith also has found references to "googlemail://", getting therefore to speculate that the protocol of electronic mail of Google could be intimately integrated with the one of IM.

It would be a clear indication that the boys of Google would be delaying the launching of GMail to do it at the same time.
Some sources:
Afriguru
Noticiasdot (spanish)
Openfutura (spanish)
Hispamp3 (spanish)