This post at Macdrifter explain how you can use Evernote as a "clipboard" of sorts for transferring text from an iOS device to the Mac. The advice is not Mac-specific but should work for any of the platforms on which Evernote runs. So you could use it also to transfer information from an iOS device to the PC, etc.
In a sense, that is how I have used Evernote for a long time. As a kind of multiple clipboard for texts that get transferred into permanent notes later. It is, however, not "my universal inbox," but, at most, one of my inboxes.