Autenozzy - no, but he's not interesting in discussing the planning stage yet, but she really really wants to - so go ahead, start not just whittering on about it and move on to actually doing somethign constructive.
Of course, he probably wants to wait until you officially annouced it to see if either set of parents offer you funds towards the wedding (unless he already has been unofficially told he could expect money from his parents).
OP - channel your excitment in to planning, but don't keep on and on about this super exciting venue and wanting to talk details yet.
I started this way and realised that DH had no idea about the list of everything that needed to be done, I resorted to spreadsheets. He had no idea why a wedding could cost £20k, "because it's just a big party" well, yes, but it's £X for flowers, £X for photographer, £X for cars, £x per head for meals (x by the number of guests we were going to invite), £x for registrar, £x for cake, £x for bridesmaids outfits, £x for suit hire for groom/groomsmen etc. once he'd seen that he could see how it can be that much and work out where we could save money, and work out how we set our budgets.
Sometimes the person who's really excited and really wants to get on with organising right this second needs to channel that bounciness into something contructive, otherwise you risk just being bloody inrritating and talking constaintly about something that's not going to happen for over a year.
ie. being organised is fine, being laid back is fine, being a wedding bore is not.