We in the XOOPS module developing group are working on a set of requirements to be met to get the "Official XOOPS Module Certification". Among those requirements will be the use of existing objects, SMARTY templates, Notification and Preferences - where this is an advantage, of courrse.
The set of requirements is not done yet, and we'll also need to setup a group of module testers/reviewers for the certification - Catzwolf is the leader of the module development and can give more information as and when it is available (as well as correct me, where I made a blooper )