What else is out there??? What lies hidden by the wretched catalogues of most institutions, where none but the staff can browse casually?Indeed.
It is not clear to me whether these homilies are entirely new or were already known from a Latin translation. But they are certainly new in the original Greek, and given that the Latin translations of Origen's works were generally pretty poor, tending toward paraphrase and bowdlerization, they are important either way. Some summary information on Origen's homilies is here. The author specifically bewails the loss of so many of the Psalms homilies.
This discovery is likely also to be important indirectly for ancient Judaism. Origen lived in Caesarea in the third century. He knew Hebrew and was in contact with the local rabbis, so his work is often influenced by contemporary Palestinian Jewish exegesis.
Bit by bit, a letter at a time, whatever it takes. Until we're done.
UPDATE (13 June): More here.