The Black Beetle, put out by Dark Horse is a retro style (check out the cover art) mystery man hero out now. You may still find an issue #0 on the shelf (not necessary to get into the story).
Also, The Rocketeer is being put out by IDW in a series of minis (usually four issues each).
And I would consider JSA Liberty Files: The Whistling Skull as closely retro.
Golden Age is kewl again! (And again, and again. LoL)
