The Infinite Dragonflight are actually future Bronze dragons, and the reason Nozdormu has been missing all these years is because he's leading them.
But it's just one of many theories.
I have heard that before. If that turns out to be the case, it will either be incredibly awesome or a terrible mistake, depending on how it's executed.
If that is the case, I assume players will ultimately kill Nozdormu. I really object to having Malygos be killable, and I expect that Deathwing will be killable in Cataclysm, and if players end up killing three of the five Aspects, things will just get ridiculous. Also, I kind of like Nozdormu, and I'm sick of my favourite Warcraft characters being turned into villians and getting killed.
That said, there are ways that could be awesome. For example, if the Nozdormu leading the Infinite Dragonflight is a Nozdormu of the distant future, and the present (if such a term can apply to such a being) Nozdormu sticks around, I'd be happy. Time paradoxes even open up the possibility of awesome stuff like helping the present Nozdormu kill the future Nozdormu.
It would also depend on Nozdormu's reasons for doing this.
Bu-bu-bu-wha? It's too early!
Is it? I couldn't remember if we do it after fifty pages or 1000 posts. Sorry.
Anyway, this gives us more time to enjoy the Halloween bar before Halloween.
And I want to change my avatar now! It's a Halloween party after all. Besides, how am I supposed to make my entrance as plain ol' me?
*Shrugs.* Whatever you wish.