Please add the ability to configure and use Social Authentication Services like authentication services from Facebook, Google or OpenID for users of the shop to log in to their user area using those services credentials.
This will eliminate the need for the user to register with the shop and allow to start using it immediately. And account for new user can be created automatically the first time user log in with Social Authentication Service.
OpenID authentication for example already can be used by Google, Yahoo, MySpace, WordPress, Blogger and other users: http://openid.net/get-an-openid/
More information:
http://en.wikipedia.org/wiki/OpenID
As of December 2009[update], there are over 1 billion OpenID enabled accounts on the Internet and approximately 9 million sites have integrated OpenID consumer support.