One of them answered here and IIRC what (s)he said was that they won't cut off the old APIs until every popular extension can be upgraded to the new api. So it

One of them answered here and IIRC what (s)he said was that they won't cut off the old APIs until every popular extension can be upgraded to the new api. So it was less of providing a poor api like Chrome and more like creating a newer and better API that also happens to be a superset of Chromes API.