I have never seen a draft this uncertain.  For all we know this could end up being 2001 draft all over with the best players coming far later.  Here is my quick assessment.

Williams = Is a tweener...so I think he has the ability to be a niche(y) star player.  Like Lamar Odom, he has a good shot off the pass and a terrific drive but he does not seem like he has a shot off the dribble...once again like Lamar Odom.  At best I feel like he heads Melo / Barkley  route and becoming a bully SF with a good shot.  At worst... and more likely, I see him going Jamison route and being an All star quality Offensive player without an identity on any team.  It seems like tweeners are doomed for being 6th man award type players (Jamison, Odom).

Kanter =   A worthy gamble (6 and 18 worthy).  Worst case scenario, Darko, Laetner, etc.  Though he has been likened to Marc Gasol and Horford, I see him more in the likeness of Tim Duncan.  Not athletic, but sound and immovable.  If he could be anywhere close to Timmy D, in any capacity, a worthy gamble.

Vesely = Joe Alexander

Biyombo = Seraphin on steroids.  I really liked the Seraphin pick and I still do, so naturally I really like Biyombo.  The one thing that has me wanting Kanter more is our team needs.  Biyombo will not be anything offensively and will be raw outside of 1 on 1 D and the spectacular weakside block.  The fact is, we already have this guy, though he is more athletic and less physical.  Ideally I would love to have both Kanter and Biyombo if it was pssible to trade Blatche for the possibility.