I hear they eventually invite you back in, but you can't gamble there anymore. So if you're kicked out of the Tops, you will eventually be able to re-enter, but you won't be able to gamble (or maybe just wont be able to cash in chips).
This is just what I've heard though, I haven't done too much gambling on the strip yet.
At the time they ban you they say some variation of "you're welcome to stay and enjoy the shows, drink at the bar, and stay in the hotel, but you're done at the tables" or "you're done taking money from us" at which time you are permanently banned from gambling.
I've been banned from gambling at every single casino in Vegas, along with the Atomic Wrangler.