CONRAAAAAD!
It's a post from June on his (public) facebook page, but I didn't see it posted. In one of the comments he says it would happen in the series finale (100th episode).
THIS IS GONNA HAPPEN YOU GUYS. CONRAD IS BACK!
Source
His Facebook
mods, this is from less than one month ago, it's news about the new season and hasn't been posted, not really that old news.