The photo is too small to see whats going on. Can you take a bigger one and did you remove soil from the top?

What a huge plant! I would cover up those roots up to what appears to be the trunk flare (or equivalent for shrubs). That may be an inch or so, probably not more. Those are not roots associated with daily watering and I would not cut them away as quirky suggested when he didn't have a picture. And a little mulch on top of that, of course.

Thanks for link to imageshack. Here is a bigger picture of the viburnum still in its Monrovia pot, though I took esh's advice and covered the exposed roots with an inch of soil since I took the picture. The one I planted is similarly exposed at the base. BTW, I never removed any soil from these two plants. It looked to me like the soil had washed away over time, sitting in the Pike's since early spring. But maybe someone who knows viburnums very well knows better..... Thanks everyone!
http://img45.imageshack.us/img45/9278/viburnumcloseupnl8.jpg

Yes, those roots are keepers. I think you're right in that the soil just washed away while it was at the nursery.

Add to it and cover with mulch. Good luck!