User blog comment:Samuelshadow16/Ruby's hidden lover/@comment-18396318-20130923072131

I'd say the romance is probably going to be confined to JNPR. There's already two couples right there. If it does get into RWBY, and we do see it with Ruby, my best guess would be someone from CRDL. We haven't seen much from them, but they might be important.

To answer your question exactly, though, I would give it to Ruby x Weiss. There's more interaction between the two fo them than there has been between any other two characters, and if Weiss is following the tsundere archetype, the "tsun" towards Ruby would suggest some "dere" towards her.