The idea of building a bridge as an alternative the Malahat has been proposed several times on the VV forums. Connecting up-island traffic to BC Ferries and to Highway 17 would appear to make a lot of sense rather than the seemingly never-ending expansion of roads going "the long way around".
Having traveled over the floating bridges on the Hood Canal and Lake Washington earlier this year it seems to me that there are plenty of options to consider that would not have to be crazy expensive or incredible design challenges.
An old article by Ross Crockford reminds us there will always be NIMBY's but when looking at transportation planning for the whole South Island I have to wonder why this is not on the agenda. I think this and improved rail would make much more sense than continuing to expand the Malahat Drive endlessly.
The BC Ministry of Transportation looked at the idea in 2006 but I find their results suspect when it comes to the bridge option. They suggested over 40% preferred a "new alignment" with only 16% backing one of the four bridge options presented. I think they need to redo that polling with people who might actually be affected by a bridge including transport operators, local residents, BC Ferry users, commuters between Victoria and points north of Mill Bay, YYJ users etc. It seems to me that a more direct route avoiding the Malahat summit would be an attractive option for a large number of potential users.