My heart goes out to Ted Kennedy. A brain tumor has to rank pretty high on the list of Horrible Ways To Go. He has had a long career in the Senate and accomplished a lot; despite his reputation as an ultra-liberal, he has worked effectively with both parties to get things done.
Still we have to ask, what now? Recent Massachusetts law (passed in 2004, when the thought of Mitt Romney getting to appoint a replacement for John Kerry horrified the state legislature) requires that a Senator must be replaced by special election, not appointment by the governor, and that the special election must happen between 145 and 160 days of the vacancy. The best day to hold the election would be November 4, the regular election day, both because it would ensure a large turnout and because it would save the state a bunch of money. For that to happen, Kennedy would have to step down between May 28 and June 12. Not a lot of time for him to figure out whether he is able to continue in office.