There will probably never be a 'vore' convention, due to the cost of such an event as well as the relatively small number of people in the vore community who would probably attend one. Though it would be pretty cool if there was such an event, I have to wonder who the guest of honors would be and what the 'dealers room' would have for sale.
As for vore parties, you can usually find at least one at any of the larger, annual, furry conventions:
Anthrocon -
http://www.anthrocon.org
Further Confusion -
http://www.furtherconfusion.org
Midwest Furfest -
http://www.furfest.org/
(Note the from what I've heard, the main hotel for Anthrocon is already filled up for this year's convention)
Some of the smaller furry conventions are starting to attract vores as well, such as Morphicon (
http://www.morphicon.org/ ), though given it's size, yearly attendance is questionable.
I don't know of any non-furry events that have any vore gatherings, so if you're not a furry, one of the furry conventions is still your best bet. There simply aren't many non-furry conventions which take place, that attract non-furry vores. Since most people can only afford to go to one convention a year, furries go to furry conventions, which leaves the non-furries having to organize something on their own, and I haven't heard of anything yet.
Some vores who live close enough to each other, will also sometimes have their own, small parties, but these are among friends and generally not open to just anybody showing up, since they're held at someone's house.