Awesome idea. It would be great to have the option to create Field of type (Person) with an option to select only 1 or many people. As Imogen said, being able to map these custom People fields to out of the box people fields during conversion would be great. In the long run, it would be great to ...

Page/Dashboard level filtering would be a huge benefit. I'd add that you should be able to identify which reports the page/dashboard filter is applied to or not. I've used this type of functionality in other PPM tools and allows to develop in a way that components are reusable.