MS Office 2013 for iPad
Well...a basic version of it at least. Microsoft updated their Office Web Apps to add tablet support. It auto detects the tablet and displays the app in touch mode by default. The buttons are slightly larger than normal and supports some touch gestures. This is definitely a step in a right direction!
I've tested it on my iPad (3rd gen) and I can confirm that all the apps do work, although right now Word and OneNote seem to be the most polished on the iPad.
Get beta access to the apps by using this link: http://skydrive.live.com/?officebeta=1