why do you think it wouldnt be possible?

Retro studios did mostly the same with metroid. A new studio used a old nintendo ip to make a new 3d game (which had a 2d predessor).

I really hope nintendo will ever make this game. GTA and Zelda both did the same in the past, and it was perfectly for both franchises.

Im really a bit sad they didnt did it instead of XBX. XBX seems to be a really good game yeah, but i would be way more hyped for a pokemon game, even if gameplay and graphics would be mostly the same...^^

Because Gamefreak makes the RPGs. It's that simple. Call it politics. The Retro situation is different because the way the Metroid license is handled isn't nearly as complicated as the way the Pokemon IP is handled. Pokemon has become more than just a run of the mill Nintendo IP. Gamefreak has just as much of a controlling stake in Pokemon as Nintendi and TPC, even if they are technically subsidiaries of Nintendo. It's complicated.

I'm sure they'd let Monolith help with the next main Pokemon game, but they'd never let Monolith do one on their own, that would compete with the handheld games. Even is we all want it. Thankfully, soon none of that will matter, because I see Gamefreak stepping up big time.

Actually, you mere have to look at the some of the successes on the N64 to show gergroy is right. Games like Goldeneye 007 which went on to sell over 8 million and build the console FPS market. WCW vs NWO: World Tour lead to numerous well received sequels and for a brief time revatilized the video game wrestling market and its publisher THQ.

Heck look outside of Nintendo, there weren't too many games like Metal Gear being commisioned before Metal Gear Solid. Or look at how Demons' Souls change the market and introduced more hardcore and difficult gaming to console players. Even Bioware's middling initial success with console RPGs paved the way for successes like Mass Effect, Dragon Age, Elder Scrolls Skyrim and others.

In the business world you must take calculated gambles in order to make any progress. Xenoblade Chronicles X may have sold a massive amount more copies... or it could have been another Pokemon Colliseum/XD and sold above average but do nothing for the console itself. Sticking a successful label will get you some sales but it isn't a guarentee to save the console.

you cant really compare colliseum to xbx. colliseum failed because it was a bad game with a good ip. XBX fails because its a good game with a bad ip.
combine both = sucsess