"different filesystems": maybe not. This new Dropbox thing is a network filesystem so it could just use normal syscalls to read and write files on any filesystem the ~/Dropbox directory and be (local) filesystem agnostic.
After all you can bypass the problem by running a Windows VM in VirtualBox with guest additions and a shared filesystem. Is another way to map the Windows Dropbox's network filesystem to the Linux one, whatever it is.
Still, very cumbersome and probably slow. I remember not stellar performances with sharing files between host and guest OSes in that way.
Hopefully Dropbox will release the API and somebody will write a user mode filesystem to interface this new service.
After all you can bypass the problem by running a Windows VM in VirtualBox with guest additions and a shared filesystem. Is another way to map the Windows Dropbox's network filesystem to the Linux one, whatever it is.
Still, very cumbersome and probably slow. I remember not stellar performances with sharing files between host and guest OSes in that way.
Hopefully Dropbox will release the API and somebody will write a user mode filesystem to interface this new service.