Hey Persian
( he's a man of mystery, he's got hidden status. 
)
I wouldn't doubt that MB has these nutty cars in development, although I can't say I understand the reasoning. They already have more cars than the Santa Fe railroad.
About the "Super SL". The SL stands for
Sports Light, but I question how light it could actually be. The SL65 weighs over 4,500lbs. and no current SL weighs less than over 4,000. And knowing Mercedes practice, it would be hard for them to shed the weight. I also wonder where the supposedly top of the line SLR fits into this increasingly cozy family.
And while copyrighting a name doesn't automatically mean the cars are in development, it's a pretty good indicator that the names will be used in some capacity, since a copyright requires active use I believe.