J.B.
I wouldn't transfer them now because you'll stress them and a stressed plant is not a big, blooming plant. Let them bloom where they are, then after both the bloom dies AND the leaves shrivel up and die on their own (early summer) you can move them any time between then and the fall. The leaves have to die on their own because the absorb the sunlight and that's how the bulb makes food for next year. If you cut the leaves off, or stress the plants by moving them before that process is complete, you might not get them to bloom as well again next year. That said, tulips generally don't bloom well for more than a couple of years anyway, so if you like tulips, plant some every fall to that you're disappointed with lousy blooms in the spring from old bulbs.
@Tracy K those ones that they sell potted up are not really good plants to put in your yard. They're really designed to be used in the pot (or transferred to another pot for indoor arrangements) and just last this season. Because their bloom has been forced, they are already stressed anyway and won't do well in the yard next year. The best tulips blooming outdoors were planted there to begin with and have never been forced.