No, you can’t uninstall just PS 64-bit in the normal way (aka: programs/uninstall).

I did see if just temporarily deleting the folder containing the 64-bit version had any ill effects.
Photoshop CS5 32-bit and Bridge did open and run as usual, BUT that is not to say some problem can or will appear later on down the line.

 My advice is to just keep the64-bit version on.

It’s not Photoshop that is being redundant, but the third-party plugin makers dragging their heels.   

In the near future, most of the major players (Nik, onOne, etc.) will have compiled their plugins for 64-bit, and you really want to take full advantage of that.

chuck