I'm a big believer in prewashing everything, especially batiks. But like others here, I mix and match them all the time with regular printed fabrics and solids. My last project was a grandmother's fan and has batiks mixed along with the other fan blades, current project is using up my old Y2K squares and there were a number of batiks in those.
I've seen discussions with people who have had problems with stitch tensions and such, never have myself but then I change my needles all the time and typically use a 10 for piecing.
Edit: Here's a picture of one of my turkey fan blocks -- is funny that there is indeed a batik in it.