I doubt it would be a good idea to judge the electronics separately. What about the corps that can create the effects w/o electronics? Part of the percussive brilliance of '06 Cavies was that all the machine sounds were acoustic in nature (most amplified, but none were digitally created).
If you add a new caption for synths, than almost all corps will now need them to be competitive. Plus, it goes back to my arguement about woodwinds in DCI. Judges need pay checks. Pay checks = $$$. I think one reason the 2 perc. judges are now scratched is partly a cost-cutting measure. Which I'm all for. From the rumors about DCI's financial struggles, it'll be good to cut some extra fat, both in bodies on the field, and also...well, let's face it: anyone who's marched before has seen what some of those greenshirts are like.