Supposedly the next Metroid is going to be on the Nintendo NX, whatever that is.
A good number of the Prime people went off to make Armature Studio, which is also in Texas. This was after Prime 3, and they are making a new IP now (working along with the guy who made Mega Man, for some reason). 2008 saw the most departures and was even mentioned in
this awkward Nintendo interview (the two senior designers featured there left soon after, ouch).
Yoshio Sakamoto viewed Samus as his daughter and didn't like the Prime guys meddling with the franchise she is in (i.e. improving it as a respectable series). Supposedly, in Other M, Sakamoto made Adam after himself, who in the game acted as this weird father figure/love interest hybrid for Samus. So Other M is not only a bad game but one with uncomfortable undertones. Good for the series. I assume he still has a job because he's been elevated as an auteur of video games (bless the Japanese).