I seen an ad where someone did have that cross, I do have weims so I do look around the web at them. The ones that I seen online were either blonde like a vizla or chocolate. Dont know if you know or not but if you took away the dilute gene from a weim you would be left with a chocolate. That is just for the typical gray color. The blues would leave you a black minus the dilute. Not that I cross my weims with anything else other than weims but I have seen other specimens and they are most usually chocolates. The body type of the vizla/weim varied to the larger stockier weim to the more refined vizla. I would think the dogs would still have a lot of "bird" and would make a respectable hunting dog. I dont know much about the Vizla's work ethics but Weims are very determined and are long lasting when it comes to their birds.
I just googled "weimaraner vizsla mix" and found a litter of chocolate pups just like tatersmom described. I haven't known too many of either breed, but the vizslas I've known have been on the anxious side -- worrywarts with fur.