- Upgrade campaigns to enhanced, either individually or in bulk.
- Set campaign level bid adjustments for mobile devices.
- Set bid adjustments for targeted locations.
- Specify device preferences for individual ads (Mobile or All).
You can read the full release note over here.
Zee, a Google AdWords support representative said in the forums to "ensure uninterrupted use of AdWords Editor, you will need to upgrade by June 28, 2013."