I just downloaded this app a few minutes ago for the iPad.
It prints wirelessly from the iPad to my USB HP printer through my Airport Express.
Says it will print to any wireless printer from iPad.
It has a decent browser to print from the web.
It accesses your e-mail which you can not only print from but send/receive/compose/file from like any e-mail app.
It accesses your contacts for printing.
It will share files on your iPad with other computers for printing.
It saves previously printed files so you don't have to keep copy/pasting the same file.
It accesses your saved pics for printing.
Whatever it doesn't access you can copy/paste into it to print (I copy/pasted a test from Notes)
It took all of 1 minute from download to successfully find my Airport Express and print a test page.
Have a look, this might just be the best $12.99 I've spent on any app.
PrintBureau Kicks the iPad Up a Notch with Easy Printing | Tapscape