I bought one (Cleveland Flowering Pear)at Lowes last October and it's got leaves and some flowers. I'm guess'n you give it time to get over the shock and get acclimated to your soil it'll come around. A little feed might help.
I've got a couple Cleveland Pear trees in the front yard here in Lancaster Co that are in full bloom right now. Of course mine are over 20 years old, and our season may be ahead of yours.
Nonetheless, I wouldn't get too concerned with the tree until you see how it is doing a bit later on into the year.
There are many things that can effect a new tree like yours in the first year especially. You don't know where the tree originally came from, and there is some shock from transplanting. Just be sure that the roots are cut out from the ball so it won't get root bound, that you have a large enough hole dug for it with good soil for it to grow in, and it is planted at the right depth and staked out, and you should be good to go.
If all else fails, I'm sure Home Depot will stand behind the tree as far as a replacement for the first growing season at least.