Hello Trustin, re-inventing the wheel is never a good thing. To me, it sounds reasonable that HttpComponents and MINA cooperate on the client side, at least for the higher level functionality. There is of course some kind of competition on the lower levels, where HttpNIO and MINA address similar functionality. IIRC, Oleg had slightly different design goals for HttpNIO. At the same time, he made sure that MINA can be used to implement the HttpNIO API. So yes, I can see potential for joined efforts: higher-level client functionality like HttpAuth and HttpCookie, and also a low-level component HttpNIO-on-MINA.
But since Java NIO is not within my sphere of interest, I have to leave it to others to figure this out (or not). cheers, Roland