It seems like in the release we're just getting transports.  Which is ok with me for now.

But: does the AI understand them?  I haven't seen the AI launch an amphibious invasion yet - which is always a tough thing to get the AI to do.

But the AIs on islands have been stuck there forever.

Because pathing alone can't do it.  On land, you can trace pathfinding between any two points.  You can't do that if you have to load the units onto a transport, calculate a path for the transport, and then unload at the other end.

Loading/unloading creates a much more complex problem.

It looks like Civ5, which has a big development budget, has to some extent given up on the problem by having land units be able to automatically turn into weak transports, and so they can just trace a pathfinding route themself.

I never said it was impossible.  But in Civ4 it didn't work very well.  It could happen, but was much less common than land invasions.  [Though there were several AI mods that improved on the core AI.]

The Total War games were absolutely terrible at inter-continental invasions - particularly Empire, which really needed it.

Its much harder to get an AI to coordinate an army with a navy than it is to get it to just use an army.