Is there one? There is a specific fix in it I'm after and really want to get that version live and tested before term starts (in a month's time).
Which fix are you talking about? There is a good chance it is already included in the latest version of 2.4.5+.
I agree with Ryan, the x.y.z+ releases occur weekly, check http://download.moodle.org/ .
As for 2.4.6, it should be the second Monday of September if it is released according to the current schedule. See http://docs.moodle.org/dev/Releases - scroll to the bottom of the page.
-Floyd