For the love of God, people: this decade doesn't actually end until midnight on December 31, 2010. 2009 is the 9th year of the decade. 2010 is the 10th and final year of the decade. We count 1 through 10, remember? Not 0 through 9. The first year of the A.D. period was 1 AD. There was never a year zero. That means that the decade, like all other decades before it, ends when the 10th year is over (i.e. 2010), and the new decade begins with the year with a one in it (2011). Thinking that the 9th year is the final year is a common mistake that was made with Y2K as well, when in fact the millenium did not change over until Januray 1, 2001. If you don't believe me, look it up.
That being said, if U2 does release another album by June, as has been confirmed by McGuinnes and Bono in an Irish news article today, (see another thread) then we may get more songs that could be favorites of the decade, as the decade doesn't end until the end of next year.