I was at the Shot Show in Orlando this last weekend. A supplier who I do not wish to name because he was obviously letting "the cat out of the bag" showed me the new Glock cartridge. On the base, it was labeled "Glock .45". I didn't have my reading glasses with me so there may have been more on it than I "saw".
It is about the length of a 9 mm round but a 45 cal. cartridge. It is somewhat equivalent in the relationship between a 45 Colt cartridge and a 45 Schofield.
I was told that this cartridge is aimed directly at the 40 S&W market. I did not get ballistics on it, but clearly it will offer greater opportunity to stack 10 cartridges in a smaller frame than a G30.