Besides the skin color and some minor difference I'm really not seeing a big difference, especially once they are put in block form. Just kidding, of course.
I'm sure there will be plenty of Orcs available once they start doing the Gondor scenes. Until then, think of this wave as your chance to build up your Uruk Hai army (and see how well they can do on the table top battlefield).
I also don't get why some people are complaining that LotRs is temporarily taking over the Castle (Kingdoms or whatever you want to call it) product slots. If there is any property that is fit and worthy to step into those "shoes" while the designers and creative staff come up with new Castle stuff, then it is LotRs (a much better successor to Castle than Ninjas or Harry Potter). I'm ready to embrace LotRs with open arms (even though the human minifigs will be peach) however, how well the sets look once we see the finished versions and how much they end up costing will determine how long that embrace will last. But no matter what LotRs will be bringing in new parts that we will be seeing and using for years to come.