Are the drivers installed?
Connect the printer directly to the USB port of the Mac if you're using a USB hub.
In PrintCenter, when you click ADD you get a window with a pulldown menu...make sure you have the proper type selected USB, IP, AppleTalk...etc.
If the printer still does not show up, it could be that you need to reinstall the Epson drivers (although they should already be installed.
Before you do anything, try reinstalling the original Epson drivers from the Jaguar Install Disc 2. Then try again and see if PrintCenter will recognise the printer.
Also consider checking around the internet for similar problems. This could be know issue.
RE: CUPS
I was hoping the printer would show up automatically, configuring the printer in CUPS from scratch is not exactly intuitive when you have never done it, but it may be done.
There is a series of things you need to do, the last being to choose a CUPS driver.
Keep in mind that there could be a different problem and this may not work either, but it's worth a try. Also keep in mind you may lose some functionality using the CUPS driver over the Epson driver. The following will describe the method to add your printer, if it still doesn't work, just delete the printer from CUPS.
Name: Type a name using underscores as separators, any mame is ok. ie Epson_Stylus_820
Location: type in your computer name in all-caps as it appears in the file sharing preference panel, although I think for a local printer it may be left blank.
Description: You may leave this field blank
click continue
Choose the protocol from the pulldown menu, LPR, USB, etc... It's a USB printer, correct? Choose USB then.
click continue
Device URI: enter this: /dev/null
click continue
From the next panel choose EPSON
click continue
Now choose the driver, this is the hard part as I don't know which CUPS driver will work with that printer. A good quess would be one of the Epson Stylus series drivers.
click continue
A message will appear telling you the printer has been added. If you can't get it to work, go to Printers and click 'Modify Printer', re-enter the information but choose a different driver at the end.