Per today's EliteConnection email:
"New Top Tier 2012 qualification requirements:
On top of existing qualification criteria, members will need to earn a minimum of 10,000 Air Canada Status Miles or five (5) eligible Air Canada Status Flight Segments on eligible flights operated by Air Canada and its regional affiliates to achieve 2012 Top Tier status. Remember, the qualification period runs from January 1 to December 31, 2011. Full details will be revealed when we launch the 2011 Top Tier program."
So it looks like qualification thresholds will probably not change, but a minimum of flights with Air Canada will be needed to earn 2012 Top Tier status during 2011.