On a iMac (3.1 GHz Intel Core i5) with OS Maverick 10.9.2 Build 13C64 I tried to load a scene previously created with Blender 2.69 in the new Blender 2.70 nightly build.
The texture is not visible in the viewport and in the rendered image.
The scene consist of two planes created by the "Import images as plane" AddOn. Shadless is activated and on one of the planes is a Alpha png texture.