Over the weekend some newly leaked AT&T documents generated some interest about references to possible LTE-based iPads. iFans first wrote about the possibilities. The references, however, were rather vague and the dates were also in question. One of their own forum readers dug into the data further and found that the iPad references had nothing to do with LTE-support.
AT&T is migrating its' iPad users (and actually has) to this new data billing infrastructure before its' LTE launch - hence, "pre-LTE". A lot of the information in the leak revolves around the core network - billing integration, new load balancers and other hardware in a datacenter (Bothell, Washington to be exact), as well as some information about their first LTE network deployment (in Redmond and surrounding areas) to start in July as a test LTE network.
He quotes the relevant segments in the leaked documents and sums it up: "they're moving iPad traffic first over to this new billing and traffic shaping platform."
So, no, the documents don't give any evidence that AT&T is testing LTE-based iOS devices. Apple is certainly working on LTE support in the future, but previous rumors have placed them well into 2012.