Just thought I'd let you know that I was able to get the Epson ABW black and white driver to work today with the new Epson printer driver for the Epson 3800 and Mac OS 10.7. (I think it's the same driver as for 10.8, so it should work on 10.8 also).
Here's the post that I found and I tried the work around and it works: http://jwallacephoto.com/blog/personal/technical-difficulties/
It's a bit funky because after you selet ABW within the printer driver you cannot save the settings. I hit "save" and it drops you back into the main print dialogue. If you then print, it uses ABW. However, if, instead of printing you double-check the settings, it has not in fact saved the ABW settings in the printer driver. So you just need to try it once or twice with an 8" x 10" and confirm it works, and then you're set.
Hope this helps.