On March 23, a rather cryptic message was published on the UO Herald:
We will publish a new client this afternoon for an art update for the Global Arc. Please make sure to patch.
It just refers to an update, not a new client, but with Publish 75 being released today, there is somewhat of a new version of the Classic Client.
The UO Team has updated the Classic Client patching functions, which is supposed to streamline the patching process for the Classic Client. It should reduce the amount of errors players receive when patching.
They have made a new installer available at UO Client downloads page.