Mark,
I went to a Rockets game in Houston a few weeks ago. The rules were no flash and no lens longer than 3 inches. I have a dRebel so the flash was pushed down and they didn't ask questions about that. Obviously, the lens you mentioned will be longer than 3 inches. I think if you could get the lens in, it would be worth it to play around with. I brought in my 50mm b/c it's all I had at the time and any zoom will probably be over 3 inches. I was in the back of the lowest level. Take a look at my pics if you want. They're not good because of my short lens, but the court was very well lit. Of course, for action shots I still had to use a high ISO.
Good luck!
Suzy
http://www.pbase.com/suzyjazz/inbox