Hi Jon - Wolfram had kindly sent me a link to download and try Workbench 3. The main updates are:
Wolfram Cloud Integration - This version has functionality that allows you to work with either a local Mathematica or the Wolfram Cloud (there is a new perspective "Wolfram Language Development").
Editor Improvements Improvements to completion - Camel case and case insensitive completion.
Unit test support improvements that directly support Mathematica 10 Unit Testing
Using version 3.9 of Eclipse editor
There are some differences but overall this looks very good.