This will be cool if they get it working right. And cheaper!!
The new YN-E3-RT transmitter will provide practically all the features of the original Canon ST-E3-RT, plus a number of important extra features. These include a built in AF assist light, 2nd Curtain Sync (Only in M mode), USB port for , and added range to 100 Meters.
If you may have missed the original announcement, YongNuo will also have a fully compatible YN600EX-RT flash unit coming at some point in the near future as well.