Here's another rumor, iPhone 5 will come to Verizon and AT&T, but only the 4G network for AT&T will be supported, with only 3G for Verizon iPhone 5.
http://www.product-reviews.net/2011/06/05/new-iphone-5-with-att-4g-only-droid-bionic-or-bust-for-verizon-users/
http://www.product-reviews.net/2011/06/05/new-iphone-5-with-att-4g-only-droid-bionic-or-bust-for-verizon-users/