I have decided to return this printer -- I was on epson support line this morning for about 1 1/2 houras and I could get the aiprint to work if I put the printer right beside my router but it was not consistently able to be accessed - -epson seems to wnat you to use their Epson iPrint utility and I want to use airprint like I should be able to.
I have an HP printer at home that works GREAT with airprint -- next time I get an HP printer.
I just spent a few hours on this problem myself. I connected the Epson XP-400 to my Airport express and it would print from my macbook, but wouldn't get picked up in the airprint. I went back over the documentation again and found my problem. The airport, and it appears the timecapsule, will not do airprint if you connect using a usb printer cable. I changed my connection to use the Epson wi-fi and added the printer again. Prints from my mac and now shows up in airprint and prints from there also. Wish I had realized before I pulled out three of my four remaining hairs. Well, I can at least print that coupon for the hair clinic now!