Magento and WordPress: sharing user registration and logins

I need to integrate Magento and WordPress for a corporate website.

There will be other functionalities in the website that will require a login (ie forum, helpdesk and maybe others…) which I would like to develop with WordPress since I’m totally ignorant at the moment on Magento and looks a very complicated system for theming and extending.

The problem is user registration and logins: which system should handle those? WordPress or Magento? What would be the best route to follow?

Thank you so much for any help or advice