Concur with Chris. Although I am not a big .40 fan, I venerate the .45ACP and the .45 GAP is, for me, a territorial imperative on a truly great cartridge.
One recent cartridge that I truly like is the .357 SIG. This cartridge, which is a necked down .40, has the requisite juice and accuracy for which I have great respect.
Glock's reference to the .357 SIG is ".357" (without the SIG reference). My take on the .45 GAP is that Glock wants something to rival the .357 SIG but the GAP is messing with the wrong legacy, in my view.