Hey, i found some new screenshots of leader heads for BtS.
Here they are, sitting bill and two others I have no idea who about.
http://pcmedia.ign.com/pc/image/article/797/797847/civilization-iv-beyond-the-sword-20070619054045204.jpg

http://pcmedia.ign.com/pc/image/article/797/797847/civilization-iv-beyond-the-sword-20070619054045657.jpg

http://pcmedia.ign.com/pc/image/article/797/797847/civilization-iv-beyond-the-sword-20070619054046094.jpg
I hope the african one is Ethiopian! They are a much needed civ.

Second one is hammurabi, that was confirmed a while ago.
The other one is, indeed, Ethiopian. Specs:
Leader: Zara Yaqob - Creative, Organized
Starting Techs: Hunting, Mining
Unique Unit: Oromo Warrior (Musketman), has first-level First Strike and is also immune to First Strikes, begins with Drill I and II promotions.
Unique Building: Stele (Monument), grants an additional +25% culture.

look at the "Everything you need to know about BTS" thread, it has a linkie to the article which has all the info on leaders