Oracle was attempting to leverage their (claimed) ownership of the trademark on the name of the Hudson Continuous Integration system to take full control of the project (otherwise open source). Most notably, they tried to block a move of the central source repository to github.
The response was a proposal to change the name. This was put to a vote among the dev community, who voted in favor, 214 to 14.
The Oracle member of the interim project governing board was invited to continue past the name change, but has apparently declined.
Not a great day for anyone, I guess, but Oracle really doesn't come out of this looking good...