TO be honest, I like the idea (and I'm a grown up man) of a minivan. I see the Sienna, and seems to have aggressive looks. But never as the SUVs.
I'd go for the minivan if they had more aggressive/sporty looks. As you said, it's the stigma it's for moms, and therefore, for some reason they look like cute cars rather than sporty cars. Make them look sporty like the new Siennas, and they will win some market back (unless people actually need AWD).