How big would a 100-200 f2.8 m43 OIS be?

I second that motion!

Just as a comparison of a translation from 4/3 to m4/3:

Specs for the 4/3 Zuiko 70-300mm f/4-5.6:

• 14 elements in 10 groups
• Front element rotates
  
• Filter size: 58mm
  
• 127mm x 80mm / 5.0 in. x 3.1 in.
• 620g / 21.8 oz

Specs for the m4/3 M.Zuiko 70-300mm f/4.8-6.7 (~1/3 stop slower):

• 18 elements in 13 groups
• Rear element focusing
  
• Filter size: 58mm
• 116mm x 70mm / 4.57 in. x 2.76 in.
• 430g / 15.2 oz

Significant size differential, 30% weight savings. If a m4/3 version of the 50-200mm f.2.8-3.5 achieved a similar weight reduction, we could expect something in the 700 gram/25 oz. range (4/3 is 995 g/35.1 oz).

That's less than half the weight of the CaNikon 70-200 f/2.8 1.5kg/3.3 lb behemoths. And with longer reach. [Yeah I know: DoF, equivalency, etc.].

It would be a very welcome lens!

--
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