AHS President Alan Dulaney notes that "Water levels in Lake Mead are only eight feet away from triggering such a declaration in April 2011, but creative water accounting, releases from Lake Powell, and forbearance by some parties may push back the declaration date by two or three years. But not forever. Excess water will disappear first from the CAP canal, potentially by 2015, then agricultural water allocations will be reduced."
A couple weeks ago, Arizona Republic reporter Shaun McKinnon (who blogs at Waterblogged) described plans for Arizona to leave part of its share of Colorado River water in Lake Mead this year. "...water officials would pass up billions of gallons that they could take from the river in 2011, hoping to keep the drought-stricken reservoir full enough to avoid triggering automatic cutbacks. Any cutbacks could deny Arizona and Nevada even more water in 2012."
Then, right after Christmas, Shaun reported that "Mexico will leave part of its Colorado River allocation in Lake Mead for the next three years, slowing the decline of the drought-stricken reservoir and possibly delaying the onset of water rationing in Arizona and Nevada" while Mexican farmers recover from the April earthquake that damaged water systems in the region.
But these are one-time actions that seem to at best only delay shortages unless the drought ends or consumption drops.