The estimate would vary depending on how many outstanding bugs there are, how many new bugs are reported between releases, and what items remain on our to do list etc.
It wouldn't be right to give an estimate at this point, but I will say it is very much a target to have a stable release before the end of the year.
Of course people taking part in the beta, albeit in test conditions, is very much so a way to help us expedite the process. The quicker that bugs are found (particularly major ones) the quicker we can declare stable and make the release happen.