Wouldn't Drift be the character that only talks in Chinese? I'm sure I saw something about one of the robots would only talk in Chinese. And he's got a bit an old fashioned asian stereotype face going on.
They did say there were holding off some of the movie toy reveals so there might be some more robot cast coming.
One thing that struck me with all the "cars on set" pics was that there wasn't any shots of air vehicles on set - which makes sense since they'd be likely added in with CGI later anyway!
But with the toys released so far, all of them are cars/trucks (and dinosaurs). And the teaser trailer didn't show any robots with flying alt modes, but did have some space ships. If there is a "Cyclonus" will it be the sole jet 'con. If so, I'd kind of hope he'd have a set of clones (sweeps?!) as generic fodder.
I wonder why there's been reluctance to have flying alt modes - because product placement is impossible? Three/Four (Starscream, Jetfire - did he actually fly in jet mode , Blackout/Grinder) is a pretty small number.