I don't think he has quite made it there either.
If ATP.com is correct (actually they are wrong...see edit below) then he has spent 75 weeks at #2, which would mean a combined total of 366 weeks on the top 2. If tennis28 is correct (see edit 2 below), then as of this Monday he has a total of 370 weeks ranked either as #1 or #2, which would mean that the earliest he can surpass Sampras is on 25th April.
Would be grateful if someone could double check as we all seem to be coming up with different numbers for something that shouldn't be ambiguous. In the meantime I'll check to see if the ATP have missed out any weeks on their website.
EDIT: Yes, it seems the ATP have missed out some weeks from their website. Does anyone know for instance what his rank was on 1st September 2003? ATP have him as #2 the week before and #3 the week after but have no data for the week starting 01.09.2003
Actually I think I just realised why...it was the week in the middle of the USO so he still would have been #2.
EDIT 2: I originally based my ranking numbers for the first post of this thread from the stats on tennis28.com but now I see that tennis 28 have changed their statistics as well. They have him at #2 for 90 weeks as of this Monday, which would mean 375 weeks in the top 2 and just 1 week away from Sampras! Now I'm even more