Yeah, it's a long list right now. I agree with some others here: Paul, Williams, Billups, Parker, Rondo. Rose could move up the list quickly, but he's mostly potential right now. Nash's awful defense knocks him down a few pegs for me -- I think Jason Kidd is still hanging on in the top ten, but probably not for long. Nelson had a great year, but let's see if he can do it again (his FG% was a bit off his career norms, and that may not be repeatable). Harris is great, but I prefer "pure" point guards to shoot-first guys (though a motivated and healthy Baron Davis would probably belong somewhere on this list).
I'd probably take Rondo over Parker going forward, though I could also see taking Rose over Rondo for the next ten years, even if Rondo is clearly much better now... Anyway, I think he'll be in the top 3 or 4 at the position for a long time to come.