Yes, they do have some things in common. Both are politicians from the small state of Vermont. And Sanders, like Dean, is drawing a lot of enthusiasm from the progressive base.
In Dean's case, it was for calling out George W. Bush at a time when too many Democrats were giving him deference for being a "war president" and indeed had given him the AUMF votes to start his war on Iraq. Otherwise, except for a strong passion for healthcare reform (which was his original motivation for running) and having signed the nation's first civil union law, Dean was an admittedly centrist Democrat. That doesn't mean he wasn't a highly partisan Democrat - he was, and darned good at it, as he demonstrated as DNC chairman.
In Sanders's case, the enthusiasm certainly includes the fact that he voted against the AUMF in Iraq. But unlike Dean, he is a true New Deal/Fair Deal Democrat. He is not just calling for healthcare reform, he's advocating extending Medicare to all Americans. He's advocating free tuition at public schools of higher education. Breaking up the too-big-to-fail financial institutions. And many other highly progressive proposals. On the domestic affairs side, he for decades has had a consistent populist economic message, and on the foreign affairs side, he has consistently demonstrated a very healthy skepticism toward putting U.S. boots on the ground in the Middle East. As I pointed out in another diary, if it had been Dean rather than Edwards pushing a "Two Americas" theme in 2004 (which Edwards would recycle in 2008), Dean might well have beaten Kerry in the Iowa caucus, but as it was, those folks attracted to the populist message voted for Edwards, who came in second; Dean faded and Edwards would go on to be seen, for a while, as the only real competition for Kerry.
But more than just the message, Sanders is so much better a messenger than Dean ever was. I'm probably not the only one here who remembers Dean on the stump and how after a while one would cringe a little bit upon hearing, for the umpteenth time, his "When I was twenty-one..." speech. To my ear, Sanders is a much more compelling speaker. He doesn't sound like he's repeating, word for word, the same speech, like Dean often sounded. And when he was doing TV interviews, I was always a little worried that Dean would say something silly or counterproductive or off-message. But Sanders, in my opinion, is remarkably polished in interviews. Since I have no fear that he's going to say something stupid, it's just a joy to watch these interviews, rather than a nail-biter.
So, no, Bernie Sanders is not the Howard Dean of 2016. He's the Bernie Sanders of 2016.