Timbuk2 Informant (medium size): great bag!
I took it over for a wedding with the following in it:
1) D7100 + 18-105
2) 35 f/1.8G
3) 85 f/1.8G
4) 55 f/2.8 AF (http://www.kenrockwell.com/nikon/55af.htm)
5) air rocket thingy
6) Kindle (never leave the house without it) in its case
I could probably also have fit a 7" tablet, and more cleaning accessories, cards etc... or even a 50mm f./1.8 prime... but not much else. However it's a small bag with a great strap (including two locks to adjust it on your back) and a rain cover.
A 70-200 f/2.8 would fit (most likely attached to the body) but you can then only fit a couple of extra primes.
Good thing is that the bag is quite tall: left compartment had air rocket bottom, camera + zoom top, middle had 35 and 55mm primes, and right compartment had 85mm prime.
Very satisfying bag.