Jimby posted a great picture of the Convention Centre and surrounding buildings in the
"Post some pictures of your city!" thread.
I don't think I'm going to mind the look of a marina and float plane airport at the base of the Convention Centre at all. Its north face will continue to soar above the boats, planes and small floating buildings there, so it shouldn't take anything away from how 'dramatic' it looks from the water. I really like this building, but it's a bit sterile at sea level - I'll take the look of a bustling marina any day over concrete piles. Plus the retail in the area will benefit from the increased pedestrian activity, even if it's just a little.
Also, the more activity on the harbour (and the seawall) the better as far as I'm concerned. While the VEC expansion is obviously a fantastic asset for Vancouver, it devotes a huge amount of waterfront space to what are primarily inward focused events for visitors to the city. Any efforts that can be made to bring the public (sort-of, in this case) and locals to the surrounding waterfront should be encouraged in my opinion.
Also, for those of you who hadn't noticed the (soon to disappear) window washing crane on top of the Shangri-la, there it is.