I would wait a little bit for the new 2.8 wide angle zoom and hope that it is a 16-35/2.8 IS at a relatively reasonable pricepoint. Otherwise you will kick yourself for buying a compromise too early. If it is not, you can still buy another lens.
I think it'll be a 14-24/2.8, non IS
I'm hoping for something a little wider like a 12-24mm f2.8. A 14mm isn't that much wider than a 16mm.
There was a patent not too long ago for a 11-24 f/4 lens from Canon. I would definitely pick that up as I could then use the 16-35mm f/2.8L II for events and the 11-24 f/4 for ultra wide landscape.
Here is the patent:
I hear what you are saying, but I've seen patents for a 11-24mm f4, a 12-24mm f2.8 and a 14-24mm f2.8.
So it's hard to predict which way Canon will go with their production lens. Unfortunatly patents are just a piece of conjecture...or paper. We won't know what's happening until it's announced.