Straight Talk breaks up with AT&T?

Looks like AT&T and Straight Talk ran into a rough patch. Really haven't been able to confirm what is happening but it looks like Straight Talk has stopped selling AT&T SIM cards from their website. Side retailers are also dumping their AT&T sim stock on Ebay for wholesale prices. If I remember correctly T-Mobile has a new 7 year roaming agreement with AT&T from their buyout breakup. So maybe Straight Talk got a better deal with T-Mobile or they possibly just got tired of AT&T's constant nagging to throttle everyone.

What do you guys think?