I searched around a bit and could not find much about staff confirmed future wipes. Looks like Jon confirmed a wipe for the upcomming 2.39, but that was the only one I have found. Beta 2.38 (29 July 2013) Will there be a wipe for sure when the game leaves beta stage? All of us who bought pizza would really like to know. Sorry if this was answered already but I searched 1 page of results for 'wipe'. =/
He did? Can't find any mention of a wipe in that thread and we're already past that build (at 2.41 - a little below that topic), and the next likely wipe is at the release or open beta of the game. Don't think we'll see any others at this rate - has only been one wipe during the beta all together. But yes, an on release wipe has been a known "fact" for a while now and and the pizza spent will be returned to you. Count on it happening, as it will.
There will definitely be a wipe when the game leaves beta, although that isn't necessarily when the next build is deployed. However, you don't need to worry about losing your pizza. It will be fully refunded (as pizza) after any resets there may be, including the one before the game goes live.
Don't you dare defile koalas with that kind of language! Also yay for launch reset i won't sleep properly if at all for a week once that happens.