He could change up the words on those ads in a few hours in the sound studio, plus/minus a bit of collected B-roll, and be ready in a heartbeat. He doesn't HAVE to go negative this time around--all he has to say is "I've done the job, my opponent has not" (unless Ed Brooke comes out of retirement in FL and runs in his dotage....then he'd have to answer questions about his romance with Barbara Walters--after he switches parties. That ain't gonna happen...).
He has name recognition, and the "likely suspects" (the ones that stepped aside--there were five or six) who were in the field with Warren from the "D" side did not even have an opportunity to develop any statewide name recognition because they bowed out of the primary process almost immediately.
Warren won, but it wasn't a blowout by any stretch. And she had an ENORMOUS amount of grassroots help. It's not all about the ads, certainly, but ads help, particularly if the opponent is undefined. Many towns--not a majority, fortunately, went for Brown for Senate and Obama for President.
That sexism thing is still happening in this state; EW won with a LOT of hard work, more than would have been needed for a male with the same portfolio. Get a load of the MA delegation--it's remarkable in that it is so damn white and male, while still checking that "D" block. All the reps are male (seven Irishmen and an Italian), save Niki Tsongas (and if that name sounds familiar, yes, she is the widow of the beloved Paul). And Warren is the first female Senator EVER from MA. We've never elected a female governor.
Brown has that immediate, statewide name recognition, no one--save Deval-- does on our team, and you're not going to see much enthusiasm in an off-year election.
It could be a problem. We would need lots of money and STAR POWER help.