As a buzz-word, "convergence" referred to the coming together of the Internet, electronic media, and telephony. Except for the fact that both both wired and wireless, non-IP telephone networks remain healthy and show no sign of succumbing to obsolescence soon, that process is now well along, by virtue of the appearance of devices that incorporate functionality from all three realms.
While Apple has become a heavy-hitter in the convergence game, they're really more about interoperability, first and foremost among their own products. This is why you'll see one of the most reliable Apple-centric rumor websites suggesting that release of the next Mac OS X update is being coordinated with v2.0 of the iPhone software.
Actually, this might be the case even without interoperability issues, since the iPhone operating system shares a great deal of code with Mac OS X, and changes to one frequently imply changes to the other, to keep them as unified as is practical. The need for interoperability, with each playing a role in functionality which spans devices, for instance synchronized calendars and contact lists, just makes such coordination that much more inevitable.
In a sense, the discipline required to pull this off is something of a bottleneck, because everything related Apple does must be drawn through it, but that bottleneck is also a door leading to a future in which all of our gadgets (or at least all of them bearing Apple's logo) really do work together, seamlessly if not effortlessly.