Yes you can use them both, only issue is... (and maybe someone else can help with this) is the activation, SINCE bootcamp will register as one hardware type, VMWare with it's built in driver and hardware emulator will register and another hardware type, and Parallels will register yet another hardware type.
Now since windows does it's 'activation' based on hardware changes etc, if a significant amount of hardware id's change, it'll prompt the user to re-activate it, if done to many times you have to call them or somehow contact them (why we're so willing to do this with windows but not with any other software is beyond me... DRM complaints anyone, bah that's for another thread) I'm unsure how you will, and again, maybe someone can help out here, short of activating with one hardware token, then totally not ever connecting to the internet again, how you will get around the different hardware tokens and re-activations by utilizing VMWare and Parallels, unless you plan on using one, waiting 120 days then using the other.
I'm sure it can be done legally (and I'm 100% positive it can be done illegally) but I'm at a loss how. Even my MSDN licenses (10 versions of every OS MS put out) forces me to re-activate.
So yes it can be done, but unless someone can post how to get it to stop re-activating when you boot up each instance, I'm not sure it'll be worth it.
