One of Guido van Rossum’s last items of business as he finished his term on the inaugural steering council for Python was to
review the Python Enhancement Proposal (PEP) that proposes a new update and union
operators for dictionaries. He would still seem to be in favor of the idea,
but it will be up to the newly elected steering
council and whoever the council chooses as the PEP-deciding delegate (i.e. BDFL-Delegate).
Van Rossum provided some feedback on the PEP and,
inevitably, the question of how to spell the operator returned, but the
path toward getting a decision on it is now pretty clear.

Source: LWN.net – [$] Toward a conclusion for Python dictionary “addition”