When will Pete Sampras's record be broken?

With 14 grand slam victories, Pete Sampras leads Roy Emerson by 2, Bjorn Borg and Rod Laver by 3. Below are the number for all those with 8 or more victories. A complete list is here.

My opinion is that Sampras will hold this record for at least 30 years. Reasons
– He’s got a significant lead over all others.
– There are too many good players today. On this list, only Borg, Lendl, Becker and Conners are reasonably
current.
– Pete might even win another major or two.
– It took Pete 13 years to win his 14 majors. No doubt, some young player will come along who dominates the game, but it will still take him quite a few years to win 15 majors.

P.Sampras  /  14 
R.Emerson  /  12 
B.Borg  /  11 
R.Laver  /  11 
W.Tilden  /  10 
F.Perry  /  8 
H.Cochet  /  8 
I.Lendl  /  8 
J.Connors  /  8 
K.Rosewall  /  8 
M.Decugis  /  8 
W.Larned  /  8

Lleyton Hewitt has to be a chance.

He’s 21 and already has 2 under his belt.

I thought Barry Bonds had at least 9 grand slams.