well the thing is that chavez has been a perennial 30/100 type (tho i believe he hit 29 last year), and he's one of the best fielding 3B in all of baseball, if not the best.
he's pretty young, he seems to be a "dude" type of guy whom people can get along with, and well, here's the thing...
he's traditionally a really slow starter. i had him in 02 and it was just like it is now.. you're looking at (and these are generous estimations) i believe .240/3/10 right now and like "wtf" cuz even troy glaus is looking like a stud compared to dirty chavez.
thing is that one of these years, prolly the year he learns to hit .275 against lefties, he might start off as hot as he finishes, and if he does you're looking at 40/130 or something.
3B isn't as deep as 1B, yet can be a sufficient power position if you staff the right guy. the reason chavez is such a big deal is because he's basically guaranteed to produce. barring injury, the worst season i see him having is like .250/25/85, so if that's your floor, you look upwards towards the ceiling and start to daydream.
people like chavez because you plug him in at third on your team and you pretty much know what you're going to get. and one of these years you figure .300/40/130 is going to happen, so thats why there's hype around the guy.