Most people who publicly predict such things seem to expect the Blackhawks to beat the Coyotes.
When you're facing a goalie as hot as Mike Smith, you obviously want to have as much firepower as possible to throw at him. With 29 goals and 28 assists in 59 games this season, Toews is obviously a major offensive weapon for the Hawks. Moreover, he allows coach Joel Quenneville to go Kane-Toews-Hossa with his top line and not have to incorporate the mostly useless Andrew Brunette.
Toews' presence does more than that. He's also probably their best defensive forward. In a series where I still expect goals to be at a premium, Toews makes it slighly less likely that the offensively challenged Coyotes will score every time he's on the ice. Over the course of four, five, six or seven games, Phoenix might score a goal or two fewer than it might otherwise, and in a series like this one, that could be the difference.