Interesting theory, Trestres. If Zelda isn't next year, then a console Pokemon RPG would be fantastic.
Also, great thread Puffy, obviously a lot of thought went into this. I've spent all day on Majora's Mask and speculating (in my head) on timeline possibilities for Zelda as well as wondering if Zelda Wii will be a 2010 title.
The thought of Galaxy 2, Metroid: Other M and Zelda Wii in the same year has me very excited. Metroid and Galaxy 2 alone are enough for me, but I do desperately want another console Zelda soon. With the game being in development for nearly 3 years now, and 4 years by next year, I think it is possible the fans' Holy Trinity will make it out. Like you said, Zelda is the weakest link-no in-game footage has been shown and Miyamoto hasn't committed to a 2010 release.
However, with Nintendo's policy of announcing a game 6-12 months from release, the official unveiling of Zelda could take place anytime between Q4 this year and E3 2010, and the title could be ready for release in 2010. Like you said, with Metroid and Galaxy 2 announced this year it's highly likely both will be out by next E3. I think Metroid will be out in the US and PAL regions by next E3(March/April time, I think) and Galaxy 2 will be a late June/July title. If Zelda was coming out, it would be Nintendo's big core offering for Christmas.
These guesstimated release dates would also fit into Nintendo's preferred method of staggering big releases throughout the year. And with all the other titles hitting Wii next year, the Holy Trinity really could top off a magnificent year.