Now with new inking capabilities, Project Spartan enables you to write or type directly on the page, comment on what’s interesting or clip what you want – then easily share this “Web Note” via mail, or a social network.
I'm really, really not sure how this is going to work in an era of single page apps. Presumably it can only really send the URL, so unless a developer has been very strict about using pushState (and good on them if they have) I think we'll see a lot of broken experiences with anything other than article web pages.
I assume it's similar to how OneNote does things, which is to create a metadata-rich copy of the page you select (as opposed to a screenshot, which isn't searchable) while keeping as much of the formatting intact as possible.
It's probably very useful if you ever do web research or need to review web content (I do), but I'm not sure this is as big a deal as they're making it out to be. Might be some box-ticking for marketing ("make sure you find a use for the pen!!!").
It looks to me that they are thinking about some sort of use case that was popular in a management meeting in an attempt to make a browser that does something different than the others. Unfortunately, this forces the dev team to implement a browser, something made for the purpose of general applications, as something more feature specific.
I'm really, really not sure how this is going to work in an era of single page apps. Presumably it can only really send the URL, so unless a developer has been very strict about using pushState (and good on them if they have) I think we'll see a lot of broken experiences with anything other than article web pages.