It depends. Are the corms soft to the touch or are they still hard? If they are hard then plant then, remember don't bury the corms and amend the soil and of course water.

Here is a link that might be useful: Propagating Perennials

If the rhizomes are still firm and have a little weight to them (not completely dessicated and shriveled), there's a good chance they'll recover and grow once planted. Of course it's extremely unlikely that any would bloom this year - possibly not even next year - but they may survive to bloom eventually. Wait until after your last frost date, then get them in the ground. It wouldn't hurt to toss them in a bucket of water for an hour before planting, too, to help them rehydrate.

You have nothing to loose but a bit of time - so try planting them. Recently, someone sent me some rhizomes from Europe and when I opened the package, they looked pretty dead. I planted each one individually and all nine are now growing vigorously. Agree with Laurie, they will need a year or two to recover. Also agree with bullthistle: if the rhizomes are soft and mushy, they're done. Sorry!