@-wahn-:
Well, after take a look again at the 10th anniversary of One Piece, maybe you're right. I was actually a little disappointed though. Seeing how Kubo, Toriyama and couple other mangaka put more details into their drawing in Naruto 10th makes it seems like they are really into Naruto more than One Piece.
Its easier to put detail into a simple headshot than it is an actual composition.
Seriously, I think the fact that everyone did Naruto, and no one did say, Sakura(not even the artists that are better at drawing girls) or a group, is more telling. Whereas the OP one had Frankies, Choppers, Namis, Usopps, and Robins, and so the artists oviously enjoyed the series and picked out a favorite.
Also, they may have been asked sooner/had looser deadlines on these. And an artist inspiration strikes, as it strikes. No one draws the same quality on every drawing. Also, the art style on Naruto is a lot more mainstream and closer to everyone's normal style, while OP hasa pretty different look to it. They might have just been more comfortable doing a Naruto piece. There's a lot of factors.
It's done dirk monkey! [qimg]http://img121.imageshack.us/img121/931/dirkmonksmall.jpg[/qimg]
…is that a hillside of boobs?