I noticed yesterday that the bike lane has been closed on the Upper Levels from Exit 4 at Nelson Creek all the way to Horseshoe Bay. Detour is Marine Drive via Wesport Road.
Construction work will begin on the bridge deck starting April 24th, 2014. While the deck work occurs, there will be insufficient width on the bridge deck for safe passage of cyclists. A cycling detour will be in place for the duration of the deck work which is expected to be complete early December, 2014.
http://www.th.gov.bc.ca/highwayprojects/Nelson/updates.html#cyclingDetour
No mention of route changes on the Whistler Fondo website. I wonder how they're going to deal with that.