If its called asp.net 7 people would think its backward compatible. And since almost everything was rebuild from scratch, WebForms doesn't exists, WCF also, most important namespace System.Web is gone, it wouldn't be fair to version it with 7. MVC API looks the same, but that's about it, everything else underneath is new. MS went long way to "emulate" old MVC and WebAPI, for easier porting of old apps.