I'll write up some lengthier thoughts on the classes soon, but until then, I'll leave a very interesting snippet from a web article.

Finally, a few races in the Eberron setting often produce beguilers. Doppelgangers and changelings are foremost among these, and at the DM's discretion, a player with a changeling PC can take beguiler as his favored class instead of rogue. The other force known for its beguilers are the rakshasa. As the rakshasa are known as spirits of deception, a DM may chose to give a rakshasa the spellcasting abilities of a beguiler instead of a sorcerer -- although to gain any of the other class abilities of a beguiler, the rakshasa will need to take levels in the class.
Though wrapped in 'mays' and 'cans', it might be interesting to someone building for a competition on here.