I have yet to see that on any roadmap shown to me. So no.
Probably not until Citrix has a sizable install base where it makes fiscal sense to throw dollars into the development....
You can always put a client agent in the virtual guest.
I'm pretty sure Xen has developed some sort of off-host or VCB like technology as well, so perhaps it's possible to script it? Pre-12.5, how do you think folks were backing up ESX?
