That whole blue ocean thing, yep. It could work out for them. Anyways, the FPS genre had a good run.

MP3 boring? Heresy!

I would agree that an online multiplayer would've boosted sales, and it should have been implemented ONLY IF it could've been done without sacrificing the quality of the single player.
Would Halo 3 have sold as many copies solely on the strength of it's single player campaign(4-player coop, notwithstanding)? I seriously doubt it. I have friends who bought the game only to play online multiplayer. They haven't even touched the campaign. I personally was slightly underwhelmed by the campaign, but the multiplayer keeps me coming back. Don't underestimate the appeal online can have.
I could say the same thing about Rainbow Six Vegas.
And who cares if Metroid's multiplayer would've had nothing to do with the single player? Using Halo again, if you've played both the campaign and the multi, you'll see they've got virtually nothing to do with each other. If multi was in Metroid and you didn't like it, just don't play that part of it. Simple.

i have a feeling next metroid will have

Prime 3 should have had a second commercial targeted towards the hardcore gamer. But I think the average xbox, halo playing, I watch G4, dude would never pick up a Wii remote anyway.

If Metroid would have had online it would have just been held to the standard of Halo and crushed in reviews hurting the game. Nintendo was wise enough to know where not to set foot.

No, it's likely that Metroid would have sold better with multiplayer...and heck, I know that I and a lot of you guys denouncing it would have played the multiplayer and enjoyed it, even if it wasn't perfect.

But they got the game out on time, which they wouldn't have with multiplayer, and Metroid isn't the kind of game suited for multiplayer, so personally I'm fine without it.

It would have only been a bonus...it's not a necessity, so it's not worth whining about.

While I can see your point Metroid Prime 3 is an adventure game as much as a shooter and as such isn't really designed for the type of play that would occur online. Even co-operative play wouldn't work as one of the features the Metroid series is famous for is making it feel like you are entirely alone (which was ruined in Hunters and would be very ruined in co-op).
Thus I think you are wrong, it simply isn't the right type of game for online multiplayer.

multiplayer and metroid just isn't a good fit to me. but i will agree on one point, someone ought to make a multiplayer focused shooter on the wii if for no other reason than to see if people will play it.

MoH:H2 is definitely multiplayer focused.

Because they want to advance their core aspects, which Mario Galaxy and the Metroid Prime series both do an exceptional job of.

All the games you mentioned are first person shooters -- and the best one, the Orange Box, is actually several different games.  HL2DM is not well known for its multiplayer, but TF2 is.  Notice that there is no Episode 2 online and no Portal online, nor is there a single player component for Team Fortress 2.

Metroid is an adventure game.  It's Zelda with a power beam instead of a sword.  Saying Metroid should have online multiplayer is like saying Zelda should have online multiplayer.  It's just not the same genre.

I'm sure you're going to come back and say "why shouldn't Zelda have online?", and this is your answer: Games should not try to be all things to all people.  Development budgets are not infinite, nor are console lifespans.  It's wonderful that Valve could make three different games and sell them in the same box, but it took them at least 8 years to make one of those games (TF2), and the Orange Box was delayed several times on account of all three games.  If Nintendo made these kinds of ubergames and released one game every two years like Valve, you'd be on here bitching that there are software droughts for the Wii.