I too am interested in batch insert/update abilities.
If I have a form submitting the information below...
...right now I have to loop over the rows and save/update/create individually, with Contact()::findFirst(42)->save($contacts); (or something similar)
What would be desirable might be something like Contact()::saveAll($contacts) and let the ORM find the primary key in the array, or require the array to be indexed by the primary key, and take action from there.
Looping through is quite fast, and we'll probably create a little helper function to handle this, but something built-in might be better optimized.