Rooted or unrooted? Where are the themes coming from? Haven't messed with any themes from the market. Rooted themes (for custom roms) would be device specific with very little overlap.
Is it from the android market? If so you should be good. I remembered I did try an iphone theme once for like 15 min. It worked fine I just couldn't stand the user interface. The market shouldn't show anything that is incompatible with your device.