[KeytarHero]

I don't really see the point on a physical keyboard. It makes sense to repurpose the enter key on a phone or tablet where there's limited real estate and the keyboard covers half the screen. On desktop/laptop, that isn't necessary - you can just tab over to the next field (or click it, for the less tech savvy), and click the "submit" button.

Also, it's right in front of your eyes, so it's clear when it says something else. Your computer keyboard isn't, and people don't usually look at the enter key before hitting it (even hunt-and-peck typers should have the enter key committed to muscle memory). Forcing people to look down at their keyboards before hitting enter would make ergonomics worse, not better.