The UKBA site mentions the residential period for Spouse as
and furtherhave been resident in the United Kingdom for at least three years (this is known as the residential qualifying period); and
have been present in the United Kingdom three years before the date of your application; and
have not spent more than 270 days outside the United Kingdom during the three-year period; and
have not spend more than 90 days outside the United Kingdom in the last 12 months of the three-year period; and
have not been in breach of the immigration rules at any stage during the three-year period.
You cannot count time you have spent in the United Kingdom while exempt from immigration control as part of the residential qualifying period
Does that mean that my wife can apply for BC on 15 June 2011 or 15 June 2012 (assuming the current rules are still applicable then) ?