You Could Use A DualShock Instead Of The Nav Controller...

If the idea of using the Move navigation controller alongside its Move counterpart seems unpleasant for one reason or another, you do have an option: use a DualShock controller in the navigation controller's stead. 

During a recent E3 2010 presentation, Sony R&D dude Anton Mikhailov busted out the knowledge that the navigation controller and the DualShock are interchangeable. This means you'll be able to roll with a DualShock in one hand with the Move wand in the other--just like the Resident Evil 5 dudes did during a TGS demo in 2009 (via Joystiq).
  

But having spent some time with the Move and its navigation controller, I can say that this alternate method of control is a bad idea. There's a reason the navigation controller is so small, light, and contoured; and it has something to do with how ridiculous it would be to use a standard controller with just one hand. 
 
The Move and navigation controller were recently priced by Sony at its E3 2010 media briefing. Expect the navigation controller, and comfort, to run you about 30 bones.