I think what helped kill the original compact van was someone's idea that minivans had to be able to carry 4x8s. Now, they are 4,500lb barges that are a tight fit in the garage, and get 16 mpg in real world driving.
As an owner of a first-gen Odyssey, I'm feeling stuck. I like the Rondo/Mazda5, but we're quite tall (me 6'5", wife 5'11") and have 3 kids (one in baby seat, one in booster, one in regular seat). Mazda5 is too small. Rondo fits a bit better, but lacks the space of our '98 Ody.
I'd like to see the S-Max and the Opel Zafira come to market. The Zafira is rumoured to be coming as a Saturn or Chevrolet at some point. I haven't seen the Dodge Journey in person yet, but we question the quality and refinement. That leaves the RAV4, which isn't quite right either.