It needs java on the server, and only if you want to use the fancy serialization (binary objects going through the pipes).
That's where they plan to make money (I think).
If you want to do the standard MySQL on the server, then you need to do XML pushups (parsing XML in both client and server).
, the super-duper organizer that will rule them all and has the fanciest calendar, seems to be flex. It makes sense that it can go off line just fine.