Have you thought about saving money on the 70-200 2.8 in the 5D2 package. Of all the weddings ive done, i havent needed anything past 105mm and when i look at all the mm's most of them are at 50. Some people may disagree, but i never see the need for a whacking great lens for weddings, unless you are doing it in St Pauls Cathedral.
Whereby i now move onto, dont get the 70-200 2.8, get the 50mm 1.4 or even better maybe the 1.2L.
A decent prime will do you more favours at a weding than the zoom.