Hayashi was asked questions recently by VG247 regarding a Other M Sequel. I know Other M was not the best in the series but it definitely had a lot of potential. It was a really great game in it's core but it had some huge faults that really held it back from being another great Metroid title. After the Prime series they have a bar and it's raised really high. Hayashi left a quote in regards to the matter but what I can add to this is that I really hope Sakamoto and Team Ninja have read the feedback on Other M and really take it into consideration.
Unfortunately Metroid is kind of out of our league as it’s Nintendo’s game, but we’re still in close touch with co-creator Sakamoto-san, so we want to do something with him moving forward definitely. It really depends on what he wants to do with the game first.