roanjohn, thank you. The size/weight of it as not as scary as it's being rumored. Basically at 28mm it's a bit smaller 70-200L IS and at 300mm I'm guessing would be comparible to 100-400 at 400mm. Weight-wise I would say it's pretty much the same with 70-200L IS. I'm attaching the image from the http://www.the-digital-picture.com …L-IS-USM-Lens-Review.aspx
review:
http://www.the-digital-picture.com …0mm-L-Lens-Comparison.jpg
Surrounding the Canon EF 70-200mm f/2.8 L IS USM Lens above (center) is the Canon 28-300mm f/3.5-5.6 L IS USM Lens retracted and zoomed out to 300mm.
