[voyager4520]

Nobody here knows when or if new models will come out, until they are released by Glock.

Davidsons Gallery of Guns among others are already listing Gen4 G19's and G23's.

http://www.galleryofguns.com/genie/Default.aspx?item=PG-19502-03&mfg=glock&mdlno=Gen+4+19
http://www.galleryofguns.com/genie/Default.aspx?item=PG-23502-03&mfg=glock&mdlno=Gen+4+23

And yes, they're completely and utterly "allocated" at this point.