Like I said in another thread, if Nintendo ever gets the main FF series back on its console, it's going to be with a FF7 remake. It's the most popular in the series. If you don't think so, just remember who won Gamefaq's last character battle. The very fact that so many people are still clamoring for a sequel just shows how popular it is. It's the Ocarina of Time for the casual gamers.
Also, I think Nintendo's been trying to acquire the "Playstation Triforce"; the 3 biggest PSX games that made people leave Nintendo for Sony.
Resident Evil: Check
Metal Gear Solid: Check
Final Fantasy 7: ...we'll see
My personal feelings aside for FF7, I would still be very excited to see it on the Gamcube. At the very least, it would give a tremendous boost to the system. Also, unlike movies, videogame remakes are ALWAYS better than the original, so hopefully any major gameplay flaws would be fixed.
I at least expect something big from Square to be announced for the GCN. I just can't imagine Yammy paying Square, his bitter enemy, to just get a handfull of half-hearted support.