The Office for iPad team does a Q&A on Reddit, here are the highlights

Microsoft launched Office for iPad nearly two weeks ago. Now iPad owners can enjoy view Word, Excel and PowerPoint documents. Have (or obtain as Microsoft would like) an Office 365 subscription and you’re able to not just view documents, but edit them as well. The apps have seen over 12 million downloads since launch. The Office for iPad team just wrapped up an AMA on Reddit where they shared a lot of interesting facts about the product. Highlights from the Q&A below.

Printing from Office on iPad is a high demand feature. The team plans on introducing the feature in due course. Source
Office for iPad team didn't want to rush the release. Spent time getting features right to avoid subpar experiences. Pleased with results so far. Source
Code between Office for iPad and Office for Mac is shared. Source
Office for iPad apps are completely native. Core logic, like Excel's recalc engine and Word's text layout code is C++ code that's compiled and shared across platforms. Source
Office for iPad now available in Hebrew or Arabic due to support for right-to-left languages not meeting team standards. Will be available when the team meets their goals. Source
Office for iPad started from a "blank slate". Team took their time to deliver highest possible quality Office experience. Source
Office for Android tablets coming in "the future". No firm time table to share at the moment. Source
The decision to ship Office for iPad came before Satya Nadella was CEO. Steve Ballmer approved the plan to ship. Source
Apple did approve the apps on the first try. The Office for iPad team is very proud of that. Source
Document fidelity is important to the Office team. Which is why various platforms share layout engines cross-platform. Source
Office for iPad team collaborates with Office for Windows team on a daily basis. The two teams are part of the broader Office organization. Ideas and code are shared between the two. Source
Office team solved a problem in Excel so that an upcoming launch would not be delayed by NASA. Source
Extensions for Office on the iPad aren't possible. Apple's App Store Review Guidelines prohibit such features. Source