I've just ordered a Tamrac Super Pro 14 (Model 614) which is the largest bag Tamrac make and it's harder to find than rocking horse droppings. I've ordered the Super Pro 14 as I prefer shoulder bags and I want to take either my laptop or netbook in it as well and can be carried on a trolley too. It's not cheap but it should take all my gear and have a bit of spare room for future acquisitions.
I've got a pair of Tamrac bags already, one is an Ultra Pro 13 (Model 5613) which I've outgrown and the other is a backpack type and is an Expedition 9x (Model 5589) which is big enough for all my gear.
I have a 5D2 and 7D both gripped and usually have my 70-200 2.8 IS L and 100-400 IS L attached, a Sigma 150-500 OS, a 24-105 IS L, a 100 2.8 L macro and a 50 1.8 as well as 2 speedlites and a ring flash, 1.4x converter and tube set and all the bits like batteries, cards, filters etc. I get all that in the backpack and I could about squeeze everything apart from the Sigma lens in the shoulder bag.