A few weeks ago, AT&T announced its Mobile Share plans, which are their shared data plans. They did say that it was coming sometime in August, and now we have a release date. The big day will be the 23rd of August if you are interested.
Competitors such as Verizon has already released their shared data plans, so it is very important for AT&T to release theirs to maintain good competition. Verizon's shared data plain information can be found here. All the information can be found in the article image on that page.