Yeah that's an important topic we're going to have to think about. I think its our natural inclination to give the same rights to simulated brains as for us meatbags, but there's some really odd perverse outcomes to that to consider too. Basically, virtual people could become tools for real people to exploit our legal and ethical systems - creating virtual populations for voting etc. I've written a little on that half way down this article: http://citizensearth.wordpress.com/2014/08/23/is-placing-consciousness-at-the-heart-of-futurist-ethics-a-terrible-mistake-are-there-alternatives/

I think we'll need to have some sort of split system - some new system of virtual rights in the virtual world for virtual people and meatbag world rights for us meatbags, basically just to account for the profound physical differences between the two worlds. That we can preserve the species and still have an interesting virtual world. Waaay easier said than done though. This is probably going to be one of the trickiest problems since someone said "so, this democracy thing, how's it going to work exactly?"