Within the existing Metroid media, the Federation already has a handful of interesting characters. Off the top of my head, I'd say that at least:

Kreatz (Metroid manga)
Maul (Metroid manga)
and Anthony (Other M)

all have a lot of potential. All are already established and fairly well liked by fans. All of them have solid identities, but have plenty of room to grow as individuals. Beyond that, all three of them have history with Samus tracing back to her days in the Federation. They could talk about their respective relations, impressions, and views of Samus, expanding her character and shedding light on her place in and relation to the universe. Both could be done without Samus appearing directly, so as to avoid the oft-criticized monologues of Other M.

Even the infamous Adam (also largely from Other M) has potential for positive character growth.

[To be continued]

Adam is often criticized for his actions and behaviors toward Samus. But the majority of what we know about him is just what Samus says about him in Other M and Fusion. Due to their history, her view is biased and taints our perspective of Adam. We've not seen much of him directly, only the version Samus has created in her mind.
Since so little is known about Adam beyond what Samus tells us, he still has a lot of story and character potential. For example, Federation Force could explore the after-effects of his brother's demise on Adam. Or show what he was doing during the Phazon War. Perhaps going to planets after Samus has left them, finding new mysteries or discoveries in her wake? Or delving into his view of his time training Samus and Anthony?
There's a lot of ground he could cover, but hasn't been allowed to so far due to the series' focus on Samus. ( Interestingly, this parallels Adam's limiting of Samus' arsenal in Other M ).

[To be continued]

These are all only existing characters, but the game could introduce new characters that are just as interesting. I'm not saying any of these existing characters should be playable, but they'd definitely add up to an interesting expansion and side-story of the Metroid universe.
At the end of the day, don't be mad about Federation Force giving Samus a greatly reduced role. If you're not a fan of the Co-op, graphics, focus on shooting, lack of isolation element, or limited exploration, that is more preference based and I won't debate those here.
But don't count the game off as a story concept just yet. With what little we know now, it has a lot of potential.
Of course, the next Nintendo Direct could make this whole idea invalid. But, for now, the game's story potential cannot be denied. So don't hate the game just yet.

Thanks for reading. I'd love to hear your perspectives and opinions on the upcoming game. But do try to keep them civil, and don't bash the game without evidence.

*Maul is actually Mauk. Sorry, 3DS keyboard is small.

Alright, you make a point.
Though I never actually played a Metroid game, so I have little idea on the plot and characters xD

Plus, that's DS graphic

You know, now I really want to see Ridley in chibi xD

there's Metroid games for the DS? iv'e only seen the one we have for the GameCube! XD
Reply: He is prince Charming!....(to me! OuO)- WHAT? WHO SAID THAT!? wasn't me. -_o