I know it would probably go against what they're aiming for (distraction-free, no social media), but it would be an instant-buy for me if I could have an email client (IMAP, Exchange), calendar (CalDAV, Exchange), RSS feeds (along with popular services like Feedly, Inoreader or your own server) and why not a service like Instapaper/Pocket/Wallabag builtin.
Being able to do work-related stuff other than taking notes would be easier to justify the premium price.
Being able to do work-related stuff other than taking notes would be easier to justify the premium price.