I speculate that Canon will soon introduce two more IS variants to existing lenses: 70-200/4 L and 24-70/2.8 L. Why do I think so? 70-200/4: If we assume that IS is more important as focal length increases, there is no logic in giving it to the 24-105/4 while denying it from the longer 70-200/4 L. 24-70/2.8: I see two reasons to upgrade it to IS. 1. It's EF-S equivalent (17-55/2.8) has one and it is illogical to have it in the EF-S line while denying it from the EF version, which is many pro photographer's bread and butter lens. 2. It's F/4 equivalent (24-105/4) has one and it is illogical to have it in the "lower" f/4 line while denying it from the "upper" f/2.8 version. What "soon" will actually mean is another issue but anyone see any fault in this logic? Happy shooting, Yakim.