Don't panic we still support devices all the way back to JDE 4.2, however 4.7 was a special case. RIM created version 4.7 for the initial Storm device and added touch support there in an incompatible way (which is why we have a separate build for that platform). A few years ago RIM issued an update for Storm and moved all of the 4.7 users to 5.0 OS.
So if you are using a blackberry device you either have a non-touch device that might still be using OS 4.6 or older or you might have a touch device which is probably using 5.0 or newer. So 4.7 is redundant except for the fact that up until now it was our recommended JDE platform for touch devices.
This version of the JDE will no longer work with the touch port and you will need the 5.0 JDE going forward, this will allow us to use some of the new API's available in 5.0 when targeting newer devices and still keep support for older none-touch devices.