Japan MS Content - Neo Tokyo

Who knows, they may already have developed the other Masteria areas..

Well, not completely, but they most likely have some ideas or concept art on how the other Masteria areas will be.

For example, CWK II is already developed and maybe even ready. NxJoeW said in one of his Q&A that they would have put the first and the second part of CWK in one patch, but he said they didn't do it because it would've been too big, and probably the second part still needed some developement, but I can bet it's almost ready if not ready.

Hate to be pushing yet another session of speculation, but could they be waiting for the Cygnus storyline to be finalized(released in kms) before releasing the second half?

We have more then a few ideas of what the remaining enemies could be, and we got some even bigger clues as to who the bosses of the keep likely are(Especially since we now know of the Cygnus masters).

As for the cyborgs(and androids), don't forget we got Krakia on its way as well.

Till then, take a look at this Mega Man trailer.