I'm afraid my response isn't going to be much of an answer to you, but I can tell you that bug
37462 is the one you want to watch. Right now pm.zimbra.com isn't showing any date for the next Beta/RC release of ZD2, and this particular bug is showing as Slotted, not Completed. So trying to nail down an ETA is pretty tough.
The last few releases of ZD have been in lock-step with the ZCS releases. According to PM the next ZCS release is currently targeted for 7/26. We can hope that there will be another ZD release at that point, but even then I wouldn't hold my breath on this particular issue being fixed. Just seems like it is a tough one for the Zimbra programmers to resolve.