if you have a Brother printer there is an app in the Marketplace called iprint&scan which communicates directly with Brother printers.
At this time there is no Epson app that I am aware of (I have an Epson).
Do a search in the Marketplace for your brand printer.
If there isn't one, write an email to the printer maker - that said, I bet they will hold off driver development for Windows RT.
Yes, there is an Epson product called Epson Connect and if you have a printer on a home net with access to the internet this set up from Epson will give your printer an email address, then you can send docs to the printer via email and it will print....
works fine on my Epson Workforce 845 AIO.
Go here and hook up and sign in. You can apparently scan to cloud etc. also.
Yes, you're looking for printers from HP that have eprint. I have the D110 and can send an email to the printers email address and it prints.
I also have the D110 and have setup an email address for it. Works well for me, some limitations but overall it is satisfactory.
Now I'm looking for a Color LaserJet/ Scanner where I can do something similar.