Apparently, Ninja Gaiden 3 for WiiU not only will feature an improved game in many of the main game aspects they are also adding in Ayane missions and Ayane as a playable character. Currently Razors edge is only mentioned very briefely in the main entry of Ninja Gaiden 3. I propose making a separate page as the Sigma games all have their own pages and this is a similar deal to those.
If there can be an Ultimate Marvel vs Capcom 3 page alongside its vanilla release, then I'm sure this could do with its own if the differences are so vast. Matter 'O fact, since this is kinda like NG3's own Sigma edition, then there's all the more reason why it should get its own.
That also reminds me to ask why doesn't DMC3's Special Edition have its own page?