Just wanted to add my five pence to this discussion...
I am also trying to get something like face expressions, because for doing little films (machinima would be to big a word for this project

) this is exactly what I need, too.
Actually, the only way to do this I could think of (and where I will try to work on) is to take the texture animation path, as most models don't have facial parts in their models. So what could work is to take the texture of the model, copy it and change the face expressions on it, recompile the a2c file and write the asisting methods. Any proposals for a shortcut here?
The other way round was to take a model with defined subparts for mouth, eys and so on and import it into Alice. Due to the limitations of import function I would consider this the hard way, though the results might be more promissing for machinima (gna, I used the m-word

, filmmaking, cartoon, etc.)
BTW given the limitations of the alice graphics-engine I was thinking about turning onto Panda or somethnig, but the Alice interface and the high number of prebuilt models is too attracting to me, so I think I will stay a while with Alice
Addendum:
OK, it is done. I added a second texture to Mary and the method talk, wich exchanges the two textures periodically. The texture exchange was done the following way
1. rename mary.a2c to mary.zip and unzip into its folder structure
2. copy the folder skin and rename the copy to lets say skin2
3. in skin2 change the image.png apropriatly (I change the shape of the mouth)
4. Add skin2 in the elementdata.xml of the main folder of mary
4a) you have to add skin2 in the children section and
4b) you have to add skin2 in the texturemaps section
5. save it back
6. zip the whole structre back into one zip file
7. rename the zip to a2c
Now you can change the skintexture of the model in Alice as you like it.
OK Guys, hope this helps, I add my Mary in the attachment and remember:
NO NUDE PATCHES (at least in class)