I still don't get the point of the 24-70 f4 lens. It's more expensive than the 24-105, has less focal length range, and is comparable in optical quality. Why? Just why? If you want noticeably better optical quality, then go for the 24-70 f2.8. Otherwise, you're better off with the 24-105 for less money.
If you're right and Canon is going to discontinue the 24-105, then will they bring something to replace it or do they want to force users to a smaller focal length range so that users spend even more money to add a 70-200 version to make up for it?