It will be interesting to see what this show looks like. Last time I saw Faith, which was on Buffy, she was still the anti-hero, with a dark streak a mile wide. I understand she gave herself up, and a lot of people expect her to return as an ally to Buffy and Angel, but personally, I still hope she retains some of that darkness. She would just be less interesting without it.
But I don't know how I would personally respond to a protanganist with Faith's demeanor. Buffy may not be perfect, but I, at least find her sympathetic. I don't know if I could be sympathetic enough towards Faith. I'd hope (and trust) that ME won't just try to recreate "Buffy the Vampire Slayer". The new show would have to have a different theme and feel, which may mean it will look a lot more like Angel. But again, how would it differ from Angel, which from what I understand, is basically about a once-evil creature now seeking redemption?
Personally, I'd be more interested in seeing ME do something entirely different from Buffy and Angel. I would rather that another network pickup Firefly than they do another spinoff of Buffy.