dhenry:
to NOT rectify and filter AC wall current directly into DC and use it?
Why rectify it at all? One LED strip in one direction and another LED strip in another direction and you are done.
Indeed, I have seen such as complete surface mount modules for direct mains use (can't find the link today alas). I believe the LEDs are back to back in pairs to limit reverse voltage - certainly I would do this, LED reverse breakdown is low. Of course you need twice as many LEDs for the same brightness, so the rectification method seems superior.