From a current Tischie
Whoa whoa hold up for a second. As a current (soon to be outgoing) Tisch film student, I would certainly recommend holding off purchasing a camera right now. You definitely don't NEED a camera at Tisch.
If you're enrolled in a production class, you get access to whatever equipment you need for that class. Now that can be anything from an SLR to some HD and super-16 rigs(even one 35mm, I believe), depending on the level of the class. Now, if you really WANT a camera, I think those basic requirements are there as a general guide to get equipment of the same general quality as those that you will be using at school.
Now if you're still fixed on buying a camera, Tisch uses some aging Sony PD150's for some of the lower level classes, a couple of DVX's and now an increasing amount of HVX-200's, the DVX's HD bigger brother. Most of the students that come in to Tisch come in thinking they want to be a writer/director and by the end of four years find a more specific interest; editing, writing, Producing, art direction... all of which having your own camera is pretty unnecessary for.
Hope this helps a bit.