Heists are once again delayed for GTA Online, so says Rockstar. The Heists were planned to arrive shortly after the launch of GTA Online and were then pushed back to a vague "Spring" release. Well, Spring has essentially come and gone and now Rockstar has delayed the Heists even further.
We know many fans have been eagerly awaiting the release of the Online Heists that we had planned to release for you this spring, and they are taking more time to create than originally anticipated. We are very sorry for the delay, and are working hard to bring them to you as soon as we can. Please know that we are focused as always on making the best possible content for you to play and we are thankful to all of you for your patience, understanding and support.

Yes, the Heists are now pushed from a vague point in a season to a vague point in time in the future that may or may not correspond with any season that man is currently aware of. Heists or Half-Life 3 will be the "chicken or the egg" question our great-great-great-grandchildren will be asking their piers. It's a trick question though, because neither one will have been released yet.