After the launch of Office for iPad almost a month ago, Office Team yesterday announced that Excel, Word and PowerPoint are updated. Updates include some key new features(like printing support) and bug fixes and can be downloaded from App Store now.
Please see the announcement on Office Team blog here.
Viewing rights for Office for iPad does not require any license. Editing rights require an eligible Office 365 subscription. Please see J.J’s blog post here for Office for iPad licensing details.