Playblasts are just snapshots of the realtime 3D view, so no glows or anything that requires a software render engine.
You could use viewport 2.0, it has an ambient occlusion feature that provides some handy contact shadowing, not really shadows but helpful in previews anyway. Plus its motion blur, anti aliasing, and depth of field can be useful as well.
Last edited by Gen; 19-02-2014 at 05:35 AM.
Reason: forgot to add something