The interim Senator from Massachusetts will be Paul Kirk, Jr., the former head of the DNC and current chairman of the John F. Kennedy Library Foundation.
"He is a distinguished lawyer, volunteer, and citizen, and he shares the sense of service that so distinguished Senator Ted Kennedy," Patrick said at a press conference at the State House. "Paul will not seek the open seat in the special election coming up in January. But for the next few months, he will carry on the work and the focus of Senator Kennedy, mindful of his mission, and his values, and his love of Massachusetts."
Kirk's pick seemed pretty likely yesterday, after Kennedy's widow and sons came out publicly in favor of Kirk's appointment. Kirk was special assistant to Ted Kennedy from 1969 to 1977, so he is well connected with Kennedy's staff and can hit the ground running.
There's also some interesting subtext about Kirk vs. Michael Dukakis; apparently, there were actually people in the activist base who felt strongly enough about a Dukakis appointment that Patrick has pissed more Democrats off, something he can't afford if he wants to get re-elected. The Globe suggests that some insiders were afraid that Dukakis would be too likely to inject himself forcefully on the liberal side of the equation into the health care reform debate, while Kirk seems likelier to quietly vote for whatever emerges.
Patrick also signed the legislation today, which passed the state legislature yesterday, making the interim appointment legally operative. However, Republicans filed an injunction in state superior court today to stop the appointment from taking effect immediately, so there may be some courtroom wrangling before Kirk can be seated. (There was some concern yesterday that the legislature didn't have enough votes to include the "emergency" provision for the bill to take effect immediately, but apparently the Governor has the authority to implement it immediately through procedural means.)