As long as the Disney trademark sign is on the back of the pin, they are tradable.
As far as what is "hot" and what is not, that is a relative issue. It all depends on who collects what. If you approach collectors mostly interested in limited edition and cast member pins, then you may not be too lucky. But, hey, give it the right amount of time and they will all be limited!
I personally collect what I like, regardless of how bad anyone else wants it or not. I am sure I am not the only one in the planet doing it, so, just find the right crowds to trade with!
Me? Well, I do prefer Animal Kingdom pins. I bought two of those Disney Store pins several months ago but the seller never shipped the pins or even refunded the money.
::snif, snif::
Oh well, have better luck,
Wanda