It's hard to say which of those would be appropriate since you don't give any sort of info on exactly what you need from a smartphone or what you have used and liked previously with another carrier. Without some basic info like this, it's hard to assess and the best way might simply be to walk into an actual store (call me a heretic!) to see which one feels right for your needs/taste.
That said, the Touch Pro 2 would be my choice, but Android is an up and comer that might make the Hero viable for your needs. I'm not much of a fan of RIM or BBs in general, but my preferences might be different from what you have used and liked. FWIW, the Palm Pre isn't as bad as I thought after seeing a friend involved in the IT/sales industry give a brief demo in person. It's not as evolved as WinMo but it seems to be a relatively capable device.
My choices are : HTC Hero( is android good, Touch Pro2 (worth the 350 price tag) , Palm Pre (is it as flimsy as it looks) or the Blackberry Tour( when is the new blackberry coming out and is this a good smart phone)? Please and thank you