Early rumours were that the fully-enabled Polaris 10 GPU might have 40 Compute Units which could be reserved for the faster RX 490 but Groenke has squashed all that.

Talking to  PCGamesHardware Groenke said that there was nothing worn under his kilt and everything was in perfect working order.

He said that the Polaris 10 GPU has 36 Compute Units and er... that is it. There is nothing hidden on that product that end users might be looking forward to unlocking.
He said:

“I can absolutely confirm with you right here, that Polaris 10 in its full configuration defined by the silicon is a 36 Compute Unit configuration there's nothing else hidden on that product that end users might be looking forward to unlocking. This is the pinnacle, the latest and greatest of the Polaris 10 product.”

So basically what you see is what you get. This does mean that the Radeon RX 490 will not be Polaris 10 based or something rather than different from what is expected. Of course it could be badger, no one ever expects a GPU to be a badger, but then again it would not be a very good one.