Five reasons why I think we're not seeing the final nose:
1) I would think that if the alphas are representative of the new grill, then they'd change the gallery pics on their website...but they aren't.
2) Somewhere (as mentioned on one of the threads here) a Tesla engineer said the "nose cone" will not be on the final car.
3) Tesla's mentioned in many places that the end design will be very similar to the prototype. I don't anticipate that they would make such a huge change and still claim to say that.
4) The majority of reaction to what we see with the "nose cap" has been negative, style-wise. Surely Tesla recognizes this, and I don't think Franz would let his front end get hijacked for a reduction in the drag coefficient of maybe 0.02 or 0.03.
5) They're doing road tests, and perhaps don't want to attract too much attention.
I lean toward what we're seeing as a temporary front end, because I find the list of 5 reasons above more convincing.