If you wish to use Google Apps, you now have to pay $50/user/year. Otherwise you're stuck with a gmail address for all your users.
This comes after Google shrunk the free number of users from 50 to 10 in 2010. I know that I was convinced to move our email to the paid version by messing around with it, but I doubt many more people will be done this in the future.
So, Google — what WERE you thinking?"