SiliconEra has done some sleuthing and discovered that Denpa Men 3 has been rated by the Australian Classification Board. The logical conclusion is that the game will be released in Australia (or otherwise why go through the trouble of getting it officially rated), and obviously in other Western markets.
Given the last two Denpa Men games were localized, it's not much of a surprise, but the last we heard (in December) was that Genius Sonority was hopeful it could be done, not that it was in process. We still have yet to hear any official announcement, but book it because it's as good as done, 3DS RPG fans!