Hi,
The NAMM show is next weekend. Wait until then at least. If Roland has some new synths they will announce, then it will be there. I've heard talk about a new sampler module but you're probably not interested in that. I'm not sure about all of the differences between the XP30 and the JV2080, but internally, they're similar. I'm not sure if the XP has the 3 insert fx or just the one (like the older JV1080). You may lack the extra outputs as well that the JV has and I think that you can't get as many expansion cards in them.
I personally don't think that swapping the JV for the XP is a bad idea depending on your future expansion plans and what other keyboards you are currently using. BTW, you did not mention which other keyboards you are currently using. That may make a difference as well.
HTH
Fernando