I didn't know you meant ice-skating. Roller blading is about the same imho
Probably the only difference is stopping. (Which I'm afraid to do on either, so I either skate to the boards or fall on my ass. xD)
If I ever got to ice skate on a really nice polished rink, i think I'd be awesome, because the place around here is free, so it's filled up with little kids all the time xD