I watched it online and also read the transcript. Here are some snippets where I think he sounds like Kerry.
...This senseless, endless war. But it has not been senseless in two ways. It has succeeded, Mr. Bush, in enabling you to deaden the collective mind of this country to the pointlessness of endless war, against the wrong people, in the wrong place, at the wrong time...
...But this country has already lost in Iraq, sir. Your policy in Iraq has already had its crushing impact on our safety here. You have already fomented new terrorism and new terrorists. You have already stoked paranoia. You have already pitted Americans, one against the other. We… will have to live with it. We… will have to live with what — of the fabric of our nation — you have already "sacrificed." The only object still admissible in this debate, is the quickest and safest exit for our people there. But you — and soon, Mr. Bush, it will be you and you alone – still insist otherwise. And our sons and daughters and fathers and mothers will be sacrificed there tonight, Sir, so that you can say you did not "lose in Iraq."...
Maybe there are more similarities but especially the end of the second paragraph seems to come straight from Kerry's 1971 SFRC testimony:
Each day to facilitate the process by which the United States washes her hands of Vietnam someone has to give up his life so that the United States doesn't have to admit something that the entire world already knows, so that we can't say they we have made a mistake. Someone has to die so that President Nixon won't be, and these are his words, "the first President to lose a war."