I think the Vikes would be licking their chops if they thought the Texans were going to match a rookie DB up against Moss.
That is an obvious mismatch. I look at this as a real problem area. If the Texans aren't able to get a pass rush, Culpepper has time and well it'll be a problem.
They will double-team him and while I don't think he'll be shut out if they can contain him well that's all you can ask for. I think Capers is a good enough coach that's he's dealt with this before. After all Marvin Harrison is a pretty darn good receiver and they play them twice a year.
This is a team you don't want to play catch with though. They are capable of putting up big offensive numbers.