Eion Bailey would be a great Dent and an even greater Two-Face. Granted, my only knowledge of him is some photos and a video interview on YouTube, but here is my assessment:
1. The "unknown" charge can be easily negated. I can easily imagine seeing the trailer for TDK and the Dent actor's name flashing across the screen and me thinking, "Don't know who that is, but he sure can act." So that argument is out the window.
2.For me, the requirement for Dent acting-wise (aside from good chemistry with Bale) is that he can play both sides of him-the brash, good-natured attorney and the vicious, merciless,half-scarred crime boss. Let's see if he passes it:
Dent looking out for Batman
Becoming Two-Face
Looks like we have a winner. All he needs is the right makeup...NOT PROSTHETICS!!!