The GUI will be released when it is ready for release, not before. The same can be said for a host of Monero's Design and Development goals.  https://getmonero.org/design-goals/, for example RingCT.

As for timelines well that really belongs in the area of speculation. Software development timelines are inherently unpredictable under the best of circumstances. Add to this that the Monero project is a Free Libre Open Source Project funded entirely by donations of: 1) Talent, time, and other in kind donations, 2) Funds or 3) A combination of 1) and 2) and timelines become even more unpredictable.

Edit: The FLOSS funding above is really the best and likely the only way in crypto currency if one wants to avoid serious government regulatory risk.