These are three covers done by the very talented Alex Garner for upcoming issues of Wonder Woman. The one with WW under attack in an alley was originally commissioned for #605, but will apparently appear on #608. The one with Artemis, Cheetah and Giganta looking down into an open grave (ominous!) will apparently appear on #611 in May. Not sure when the third one is going to appear.
Source: http://alexgarner.deviantart.com/