It makes so much sense I'm shocked you folks haven't done it yet. C'mon Hasbro! You guys own both properties outright, you know for a fact that it's an idea that can work - it's been done successfully a few times in comics and even in animation to a smaller extent, and it just seems like such a natural. Both brands have even been your staples since the early eighties! Why not combine them?
I see opportunity for major financial success in a line of Transformers toys based on original G.I. Joe: A Real American Hero vehicles sporting both Autobot/Decepticon and Joe/Cobra logos!
I imagine transforming versions of such cool and recognizeable Joe/Cobra classic vehicles as the original Cobra HISS tank, the G.I. Joe MOBAT tank, Wild Bill's Dragonfly chopper, the Polar Battle Bear, the Skystriker (you've already got plenty of toolings for this type of fighter jet anyway), the ASP assauly pod, Killer Whale hovercraft, Deep Six's SHARC submarine, the Cobra Rattler, the list goes on and on! Just like this:
the Joe VAMP or Cobra Stinger (or both!)
Silver Mirage motorcycle
Snowcat (I notice you've already done this one - without the Joe logo)
Cobra "Trouble Bubble" flight pod
Serpentor's air chariot
Cobra Night Raven
Joe Tomahawk copter
Sgt. Slaughter's Triple T
Dreadnok Thunder Machine
Cobra Buzz Boar
the Mean Dog
Phantom X-19 Stealth fighter
Skystorm X-wing chopper
Iron Grenadiers AGP, DEMON, and Destro's Despoiler
Joe Thunderclap (three vehicles in one = three robots in one!)
the General with Locust helicopter
Mobile Battle Bunker
Motorized Battle Wagon
Even the big boy, Holy Grail G.I. Joe vehicles such as:
all of the Battle Force 2000 vehicles (hey, even the originals already kind of transformed in a battle base anyway!)
G.I.Joe Mobile Command Center
the Defiant Shuttle with Launch Complex!
Cobra Terror Drome
even the USS Flagg!
...and that's just the ones I thought were coolest! Lots of possibility for making lots of money and getting me the cool toys I want!
I admit that I've never been a huge collector of Transformers toys, but I'd certainly buy every last on eof these! I'm certain they'd be a huge hit with kids and collectors alike! You could even use it as an excuse to do a special animated video to help sell the line! The kids would go nuts!
I even see how success could be had in producing a line of 3 3/4" scale transforming vehicles based on some of those mentioned above as part of your regular G.I. Joe figure line with minor transforming capabilities that could still accomodate the figures! You could even dsign and produce a line of Joe and Cobra figures with Autobot/Decepticon styled uniforms with appropriate logos to drive the things. How could you possibly lose with toys such as these? It's the best of both worlds - your two most successful properties combined into one gigantic money making machine! Plus, we'd absolutely love ya for it! C'mon, whatta ya say?