If someone is using one of the online Office 365 applications, it would be great if you could print directly to a universal print queue that is accessible by that user in the tenant.
This would make it much easier to print from the online applications, rather than having to download the file and print it from the fat client, or downloading a PDF file and going through an additional operation to print it. This also enables a printing experience from ChromeOS or Linux devices, as well, at least for Office documents.
I would think this would extend to the mobile apps, as well, but I think there is already a suggestion for that.