Well you can compare this to xtreamer as its cheaper than xtreamer by 30$ odd. But if you need to buy a wireless adapter the cost may increase as
I cross checked on the WDTV website it says u can use a wireless USB attached connection so it may work with the same. Rest most of the features are same more the less.
But xtreamer is tried and tested, once wdtv2 is out and is being used by the masses we can get a good feedback and review on the same