Eh, I think they will cgi the lower part of the mask, but who knows. we will see..
Well, to be fair, the Black Mask during Doug Moench and Kelley Jones' 1990s comic book run (which is a MUST if you're a Batman fan) had quite a peculiar personality. Different than Ewan McGregor's in this movie, but still peculiar.
The writing doesn't do enough to characterize Sionis other than a hothead ganster. Ewan was good though.