One of our editors posted this on our in-house blog.

     If you need to bring a layered photoshop file into Avid while preserving each layer (including blending modes), do it via AvidFX. The interface inside AvidFX is more similar to Photoshop, making it much easier to deal with layers than trying to do it inside Media Composer.

Lay down your video track(s) inside your MC timeline. On the top track, apply the AvidFX plug-in. Go in to effects mode and click on the folder icon to open AvidFX. Once inside AvidFX, go to the timeline window and select Track->New Media->Still Image File. Navigate to your PS file and Open. This creates a flattened layer track. Click on track you just imported and select Track->Convert to Container. Twirl down the track and you have all your layers. Cake.