Onedrive integration is all that is missing now that we have Microsoft Office for iPad and have new a subscription fee to pay to use it. Onedrive comes with a cloud storage account, and most people would like the integration to Onedrive more than ever now, to save and send links from Onedrive.
Do them all: Dropbox, Google Drive, OneDrive, Amazon....
Updesh Singh Dosanjh commented
Would be a great benefit to save to OneDrive