yes, this unlocked phone will work on any network. I bought this phone about 2 months ago. I have att but my wife has Verizon (different work plans) and her sim card works in my phone no problems.
Unlocked basically just means you get the phone as the manufacturer built it, with the stock manufacturer version of Android. Buying the carrier version is essentially the same except that they put their own slightly different version of Android on it (locking the radios to only work on a given provider as well as putting different apps on the phone right out of the box).