New L Series Lenses coming out with the 5D Mk3?

[neuroanatomist]

Look at the progression, what makes you think it will stop?

UWA
20-35mm f2.8 (1989) -> 17-35mm f2.8 (1996) -> 16-35 f2.8 (2001)
Normal
28-80mm f2.8-4 (1989) -> 28-70mm f2.8 (1993) -> 24-70mm f2.8 (2002)
Tele
80-200mm f2.8 (1989) -> 70-200mm f2.8 (1995)

Allow me to update your progressions so they are current:

UWA
20-35mm f2.8 (1989) -> 17-35mm f2.8 (1996) -> 16-35 f2.8 (2001) -> 16-35mm f/2.8 MkII (2007)
Normal
28-80mm f2.8-4 (1989) -> 28-70mm f2.8 (1993) -> 24-70mm f2.8 (2002) -> ?
Tele
80-200mm f2.8 (1989) -> 70-200mm f2.8 (1995) -> 70-200mm f/2.8 IS (2001) -> 70-200mm f/2.8 IS MkII (2010)

So, as you can see from the above, in two of three classes the progression has stopped, and the remaining class of 'normal' zooms has three entries compared to four in the UWA and tele classes.

So, given that trend, and granted the n is low, the logical extrapolation is that the next normal zoom will remain a 24-70mm, with improvements in the optics, the addition of IS, or both, but no change in focal range.

Lets say we were to frame at 70mm, would we choose the 24-70mm or the 70-200mm ? And why?

Personally, I'd choose the 70-200mm f/2.8L IS II over the 24-70mm f/2.8L for that shot at 70mm.  Why?  Three reasons - first, the IQ is better, second, if the shutter speed is marginal then IS might help get the shot, and third, I don't have a 24-70mm f/2.8L... 

[EYEONE]

Lets say we were to frame at 70mm, would we choose the 24-70mm or the 70-200mm ? And why?

Personally, I'd choose the 70-200mm f/2.8L IS II over the 24-70mm f/2.8L for that shot at 70mm.  Why?  Three reasons - first, the IQ is better, second, if the shutter speed is marginal then IS might help get the shot, and third, I don't have a 24-70mm f/2.8L... 

I agree. I'd use the 70-200 over the 24-70. IQ is better.

[spaceheat]

The 24-70 2.8 and the 70-200 2.8 are the perfect tag team. The 24- 105 2.8 is just too much overlap IMO,

I prefer having some overlap on zoom lenses. In the real world it makes shooting much easier, not having to stop and switch lenses when a subject moves or to get just the right framing.

The pair of the 24-70 and 70-200 implies that most people shoot with two bodies. Many working photogs, as well as others, prefer to use a crop with the 70-200 for extra reach, while using a FF with the 24-70. Constantly changing lenses during an assignment is a pain, I agree.

I would imagine that most would agree that they use the short zoom for close proximity and the long zoom for when they hang back to get the candids. I have personally have never wished for extra length on the short zoom because the type of shot that I would be getting with the longer focal length is covered by the long zoom.

If you ask me... Canon really needs to develop the 200-400 at f2.8 instead of f4. The combo of the 70-200 and 200-400 would be great for sports journalists.

[neuroanatomist]

If you ask me... Canon really needs to develop the 200-400 at f2.8 instead of f4. The combo of the 70-200 and 200-400 would be great for sports journalists.

I'm not sure that a 200-400mm f/2.8 - a lens that would likely weigh >15 lbs and cost close to $20K - would be 'great' for anyone...

[Meh]

If you ask me... Canon really needs to develop the 200-400 at f2.8 instead of f4. The combo of the 70-200 and 200-400 would be great for sports journalists.

I'm not sure that a 200-400mm f/2.8 - a lens that would likely weigh >15 lbs and cost close to $20K - would be 'great' for anyone...

Totally agree with that.  There is no panacea in optics... there is always a trade-off.  The 400mm f/2.8L IS II is already 8.5 lbs so neuro's estimate is probably close and therefore it's just not portable or cheap enough for mass market.