MySQL Workbench 5.2 edition - Unable to establish the connection
I hope your problem might have been already resolved. However, I recently had a similar experience and I had to do following to resolve it.
1. Launch MySQL Workbench (Mine was 5.2.36 CE Revision 8542)
2. Double click on a server instance to manage the server instance
3. Goto Users and Privileges 
4. Select root or other user you wish to check from the list in "Server Access Management" tab
5. Change the "Limit connectivity to hosts matching:" to IP that you are using to connect OR just change it to "%" to remove the IP restriction.&lt;6>
6. In my case I had to change it to "%" to make it work.

Hope this will be helpful to someone, someday!
Cheers
Manish.