Big changes afoot at AT&T. Dan York has resigned from AT&T, with Jeff Weber appointed to pres, content and ad services, according to an internal memo obtained by CableFAX. No immediate word on York’s departure or where he may be headed. Weber, who was previously vp, U-Verse and video products, will be based in L.A. and report to AT&T Services evp, home solutions Lori Lee. York joined AT&T (formerly SBC) in ’04, leading its video content strategy and acquisition. Prior to that, he was svp, programming and dev at In Demand.