Nice. You might wanna include a way to remove duplicates based on G+ IDs. Also some way of removing yourself from the list? Maybe use Google accounts to connect too, so you can verify the profile owners and don't have to ask for an email addy?
It shouldn't allow duplicates, I'll work on the rest.
I updated my G+ profile after adding myself to the HN list. Updated profile does not reflect on the HN G+ page.