I just purchased the WHMCS WP Integration to try. I was previously working with the WHMCS Bridge + PRO (SSO) extension from Zingiri (support responses are slow and promised updates seem non-existent).
Ideally, if I'm going to use this plugin, it would be nice to be able to have an SSO where if a user is created in WHMCS it gets created the user in the WP DB automatically, and vice versa (or at least give the admin the option to "upgrade" existing wp users to also be part of WHMCS). If a user is deleted from one, deletes from both, if a user changes info/pw it changes to both. This would allow for clients/customers to take advantage of other WP Features. (ie. roles, create/edit posts, comments, etc)
Is this something that will be done in the next little while?