If they stopped preaching (and this would not affect their tax exempt status) it would be embraced with open arms by most JW's. It would lift a huge burden as I'm sure many of us felt when we stopping going door to door. Of course there would be some spin on it like we'd be reaching more people using the internet in areas currently unaccessible - masking the real reason that it was saving lots of money / reducing law suits.
Perhaps the dubs would be kept busy by doing more personal study and have to pass exams - more of a scientology education model. The weekly meetings might have an exam and then review format like the old rotten review, but using some software developed by the WBTS (congregations would contribute to this under licence). Thus weekly exams with published scores to show how spiritual people were or humiliate those less able. Of course it would also force regular attendence. Anyone falling below certain figures would require tuition by the better members on the other meeting nights - again all using the carefully controlled publications and source material from WBTS.
mmxiv