LR2 has more features and functionality than NX 2. It is a complete photo cataloging and management system. After many years of using Photoshop I could never get used to U-Point technology in NX 2. Also, LR2 has much better memory management and performance than NX 2.
Regardless, I suggest that you try both products for their full trial period and decide which is better for you.
I chose LR1 over NX, and with the new features available in v2, it's even better. The two things NX offers that are the biggest "draws" are control points and the ability to read camera settings. With the picture controls available in LR2, it's 99% there. The control point system that Nikon uses is very intuitive, but there is so much that LR is untouchable doing, there was only one choice for me. If you can only run one, my vote would be LR.
I think you need to define your terms.... If you want(arguably) the best RAW converter for Nikon files or want your camera settings applied in conversion then NX is better, hands down.
If you need to import, organize, keyword, sort, and select large numbers of files efficiently, then Lightroom is better or you need another program to go with NX. If you print, the Print module in LR is 'way easier to use than NX. If you need a slideshow, LR is your only choice.
I have and use both. I see NX as a RAW converter program, LR as a more versatile tool that I can open up, stick a card in the reader, organize, select, etc. my files and wind up with a slideshow or a stack of prints without ever having to leave the program.
I don't view the two as equivalent in functionality so the question of which is "better" than the other is meaningless(to me) without further qualifications.