I think it's a good benchmark of their real intentions whether they interfere with those at all. At the moment, because any user can bail out to an IMAP or POP client, including 3rd party web services that behave as those, there is a natural limit to how obnoxious Google can be. If they degrade their native web inbox sufficiently, people will switch to alternatives in droves (I already have long ago).
Indeed, we'll know their real intentions once they interfere with those services, however a bad precedent has already been created: their jabber/xmpp service.
Anyone with Android phones, what's the default way to check your emails, IMAP? If yes, then there is still some hope. :-)
