It looks like we are close to seeing the end of the Nokia Browser. Why? Microsoft has adopted Opera browser as the default browser for the newly announced X2 and the rest of the X range of devices. Like Opera, Nokia browser offers data compression, so users are not going to be missing that feature with its benefits of faster browsing and reduced data costs.
It is very likely that Microsoft sees no point in developing two browsers in-house (Microsoft is already solidly behind IE Mobile). Why have a team working on IE Mobile and Nokia Browser at the same time? Perhaps eventually we might even see IE Mobile available on the X range some day?