As many the months maybe...Or... years! This is a rumors site and everyone can write his or her BS! We simply do not know. For now I prefer to enjoy my TS-E 17mm. Less wide but still wide enough, plus having Tilt and Shift capability (and anyway the 14-24 is likely to have an equally high price).
A shifted stitch gives you an effective 11mm fov with a 40+mp sensor, medium format quality for comparative peanuts. A shift stitched 24mm TS-E image is even higher quality and more "normal" fov, and you can use filters on it.
Well, YES and NO. You must not shift a lot since it will cause vignetting in one side and it will impact the quality.
Plus you have to shift the camera and not the lens. To do that properly you need the HARTBLEI TS Collar for 500+ euros!!!
With that amount of money you can get a panoramic solution and use more lenses...
But generally 17mm is enough for me and I quite enjoy my TS lenses.