Which Big Summer Tours Are Canceled?

Two big summer tours were put on hold today until 2011. The first being leg two of U2's North American, No Line on the Horizon tour originally scheduled for this summer. The band had to bail because lead man Bono needed emergency back surgery and has been advised by his doctors to lay low for awhile.

The other tour that has been canceled is scratching a few more heads. Christina Aguilera has postponed her Bionic Tour until next year due to other commitments. The tour was suppose to extend off of Christina's album which is being released two weeks from today on June 8. Christina's people have said the postponement is due to album promotion and promoting a movie titled, Burlesque, which she stars in and is hitting theaters in November, but inside sources are reporting poor ticket sales may be to blame.