MiniBIGS recently posted this picture on Flickr of an upcoming Mario and Luigi minifigure pack. I personally scanned the site to see if these items are on sale yet, but couldn't find them. I imagine these will be available soon.
While you are waiting, check out miniBIGS current selection. Lots of original creations and several offers which combine stuff from several custom houses for desired effect (think Halo figs with BrickForge armor and BrickArms guns).
(Via miniBIGS Flickr stream)