If this is done right AOL would adopt a standard that would allow interoperability.
The way its looking right now in the voice/video messaging scene is we're gonna have communication islands and the only way to reach someone is to run five different service's clients.
Yes. Google did the original work for Jingle, but passed it to the XSF for standardization. That work has been done for some time and implementations have been appearing in various places.
Even so, I suspect it will be a long time before Skype, Apple, and everyone else does anything but try to set their own standards.
This works over Flash, which means you're confined to RTMP... while it's possible to tunnel a more standard protocol on top of that and open up the other end to third-party clients, (or simply gateway to $protocol), I doubt they've thought that far out yet.
There are pragmatic reasons for the fragmentation we're seeing, although those don't necessarily correspond to the customer's favored outcome. Federation reduces the stickiness coefficient of your product, and forces you to design your application around a protocol that may not fit your needs ideally, cf. Skype's supernode architecture.
The way its looking right now in the voice/video messaging scene is we're gonna have communication islands and the only way to reach someone is to run five different service's clients.