Messi is definitely a phenomenal passer. I have been really impressed in the last year with the improved weighting of his through balls (not that they were bad before!). It seems like I have seen a lot of Messi through balls in the past year where the striker (generally Pedro or Villa) do not even need to take a touch on the ball beyond the shot itself. This is insane. The ball really needs to have the perfect weight to do that.
He is very good at the killer ball now. And given that he is a Barca's tiki-taka player, I think it's safe to say he is quite a good short, possession passer too.
Still, though, I think some people here are being a bit silly insisting he is as good or better than Maradona at passing. I think Maradona would generally be considered in the top 5 EVER in passing (my top 5 in no particular order would probably be Maradona, Zico, Laudrup, Platini, and Zidane) and certainly in the top 10. The man averaged an assist every other match in both his club and international career! Messi is a great passer; he is one of the best in the world right now. He is not, however, one of the top 5-10 in passing EVER.
He is still quite young, though, and passing generally improves with age. Given how much he improved upon this last year, I don't think it's unreasonable to think he could reach Maradona-like heights in passing in the coming years. Consider: at Messi's current age, Maradona was just beginning his first year with Napoli. I dont think people would have said he warranted a top 5-10 in passing ever spot at that age either.
