The Roach appears to be formidable opponent for all the races. Not much is known about this unit yet but it looks like it does some sort of splash damage with green acid. With the loss of the Defiler, ...

Mutalisk (Classic) Mutalisks are the Zerg’s primary flying unit ... Note: One of the gameplay videos had a Q&A and in the background it is mentioned that all units are being planned to be infestable ...