The short answer about the camera is: It depends.
A point and shoot digital is not likely to be a problem at all. Although you are not supposed to take video with it.
SLRs and DSLRs, and the lenses in particular are looked at with much more scrutiny. Because you are part of a promo you may have a better chance to get in with a DSLR and long lens. The rep from the Leafs or the company involved in the promo should be able to help you with that. You'll get a special coloured band to put on you camera, or camera bag to say you're "checked-out" and good to go.
I have been to a couple of games as part of a special promo and went through this process. I have also gone to a game with a regular ticket and had my long lens put in a secure lock-up because it was deemed too long, but not every time . The security people, and then a MLSE rep when you complain, will tell you it is a league (NHL) policy, however when I've gone to Buffalo and Ottawa for games I've had no issues at all and have been told that it is the individual arenas to set the policy. In Buffalo the only thing I was told was that I was not allowed to use the Camera holes in the glass down in the corners that the pros use.
The choice is yours, but I say bring the big stuff and have a point and shoot has a back up.
Pregame warm-up from the penalty box November 2009
Toscala stops Ovie in the shoot-out for a Leafs win.
Leafs v Canucks October 2010