I was really hoping we could get Brandon Small and Jon Benjamin to play the Pesto brothers, but they're delightfully quirky enough to be the next Walter and Perry.
They showed up a couple episodes ago (in Art Crawl). They're voiced by Sarah and Laura Silverman, adding another great comedian to an already talented voice cast.
I'm well aware of their appearance in Art Crawl, hence the reason of my post: I'm well aware of their "Walter and Perry" like mannerisms there (especially the hints of their "alternate lifestyles"), so seeing them actually be twin brothers was somewhat of a surprise to me.