I realize this question would be highly subject to unknown variables, but I have to presume a few devs are at least partially interested in onion features and someone might have an idea where load balancing (similar to I2P's multi-homing) might fall in their priorities when it comes to working on Tor Hidden Service features.
1 Answer
Yes.
I imagine there will be quite a few improvements made to hidden services in the coming years.
In fact I think work is currently being done on exactly what you're describing.
Draft proposal for scalable Hidden Services