none of the classic G1 toon or comic designs, nor the updated IDW, Dreamwave and FOC designs have huge differences from each other. Same colourschemes and alt modes for starters, (well, they could in theory do pre-earth alt modes, which wouldn't suck but also wouldn't sell these to many people) and the general look of the robots is pretty similar from continuity to continuity.
just like characters such as optimus prime, starscream and ratchet are always easily identifiable on sight alone, so too are grimlock and the rest of his lightning strike dudes. I'm honestly not sure what a 3rd party could do that wouldn't be a rip off of the Masterpiece if they go for complete G1 accuracy, so expect these will probably be along the lines of most 3rd party figures and bear all the familiar features of the characters we know, but with their own unique takes, perhaps inspired by the slight variations on the characters looks over the years.
of course, if there's repaint potential they may choose to make them more ambiguous, like FP did with their Insecticons but those were done in such a way as to be pretty close to both designs without too much change needed. mostly the new paint job did the trick. might be harder for the dinos as there are so few others who share their alt modes and transformation schemes. more likely is a g2 repaint or maybe an SG one of some kind. maybe they'll be happy with the money for the normal coloured ones.
I'm personally hoping for something very close in design to G1s, with some extra detailling, and some additional weaponry maybe, so they'd look good taking on one of the 3rd party Devys or upcoming Predacons.
edit: I would love a version of Swoop in his G1 Marvel pre-earth mode though...or should I say Divebomb?
assembling a Neo-G1/TF:TM cast. Please PM if you have (or know of) the following at a reasonable price: Classics or Henkei Prowl, Astrotrain, Ramjet, Skywarp, Sunstreaker, Sideswipe, Blurr, Perceptor, GDO Wheelie and Springer, or 3rd Party Motobot Arcee, FP Springer, iGear Ratchet and Ironhide, City Commander (and/or Ultra Magnus), Starscream (deluxe) Coronation add-on, or Spike and Daniel in their Exo-Suits.