We have discussed such option with Martin Dougiamas in July.
It would be really a bad idea to remove Outcomes from Moodle.
1) Many universities (specially in France) use outcome for Competency evaluation since the first Outcomes implementation back to 2008.
If Outcomes are removed it
will be very difficult to migrate to Moodle 3.0 for a lot of institutions
which are yet involved in Competency based Education.
This would be a very bad signal to the Moodle Community.
2) Outcomes is a really powerfull tool which can be used to competency evaluation throughout any Moodle Activity.
3) Il lacks of a visualization interface (The Grade module is awful for Outcomes' display) so I have developed a specific module called "Skills repository" ("Referentiel") which is a kind of specialized portfolio for certification and Skills follow-up in Moodle.
You can have a look here : http://docs.moodle.org/en/mod/referentiel/view
Sources for Moodle 1.9 to 3.0 are here : https://github.com/jfruitet?tab=repositories
4) Many contributors to the Competency Framework specification forum emphasise the need of a granularity at the Activity level (and furthermore a Question level for some contributors) .
If a mechanism based upon Outcomes is kept in Moodle, we have not to develop specific code to pull skills evaluation in Competency Framework. Cron will do the job transparently by the way of Outcomes evaluation.
This is exactly what I have implemented in the Referentiel module.
I am ready to contribute to the code integration of Competency Frameworks and Learning Plans in Moodle 3.1 to deliver a conversion tool from Outcomes to Competency Framework and perhaps at last to get rid of Outcomes.
But I can't do nothing until Moodle HQ publishes the Data model (relationnal tables) and an API. So Outcomes have to be kept in Moodle 3.1 until this conversion tool will be developed.
By the way with Outcomes in Assignment I do not use grades (except for Absence / Presence evaluation)
The Outcomes scale is "No pertinent", "Insufficient", "Good" but I may use something more detailed like a LOMER scale.
By default the threshold of certification is the last value of the scale (i.e. "Good"), or what you like when using Referential module.
I hope that Competency Framework implementation in Moodle will permit to get rid of any specialized portofolio like Referentiel module :>)) but we have to make it really powerful to capture all what we did before this implementation.