Microsoft has been horizontally integrating features at a much faster pace over the last few monthsand it looks like we are starting to see another feature jumping the product gap. If you have an Outlook.com email account, Microsoft is rolling out, or possibly testing, a new way to save attachments.
As you can see in the images in this post, by clicking on an attachment, you now have three options: View Online, Save to OneDrive, or Download. If you click the OneDrive option, it will save the document to your cloud storage which is quite handy as then you can access that document anywhere you have a OneDrive app installed.

Neowin