Ichiro (I have a feeling he will be hitting .300 or better well into his 40's) or Mauer might have the most when it's all said and done.

As a matter of probability, the answer is probably A-Rod or Jeter because of the number of hits they have accumulated already.  Still, I figure Pujols will probably average 150-160 hits a year until age 35, and he's a much better hitter than the other two.  He'll likely still be getting his hits at age 41.

A-Rod or Jeter just because they both can fall down the defensive spectrum quite a bit and still keep playing.  Pujols is amazing, but is 800 hits back of A-Rod and 4 years younger - possible to catch up but not easy - plus no matter how well he plays first base he still has nowhere else to go if his defense falters.  Mauer has the catcher injuries as a major risk, and everyone else is too old or too far back to catch up.

As to Ichiro - he has 2030 hits at age 35 - normally you'd have trouble picturing a guy at that level making 3000 but given he has yet to have under 206 hits in a season I have to think 3000 is likely (weird as it sounds).  He also has 1278 hits in the Japanese League (NPB - Nippon Pro Baseball, the highest level in Japan).  So he has a shot at Pete Rose's record if you combine the MLB stats and NPB stats (Rose has 4256 plus 427 in the minors = 4683 pro hits, Cobb has 4189 MLB and 166(+) minor league = 4355).  Thus Ichiro, to set the pro-baseball record, needs 4683 - 1278 = 3405 hits in the majors, which he'd reach by age 42 at his current pace of 200+ a year.  If you figure he is the type to play until they drag him off the field (and he seems that type) then playing to his mid-40's is certainly possible thus making that mark above a 0% chance of happening.  To set the overall major league record though he'd have to last to age 46 at 200 hits a year which is asking one heck of a lot, let along playing until 50 with under 200 hits on average.  I'd love to see it, if only to remove (#&! Rose from being able to call himself 'the hit king' and to stop the people saying the HOF is missing something by Rose not being there as he is the all-time hit leader.

 Total thur 29AvgAvg per 162 gamesPujols1717191200Rodriguez1901158194Jeter1546172208

 A-rod had a huge jump by being a regular a year before Pujols and Jeter, but has the lower avg partially due to having cups of coffee in his age 18 and 19 seasons. Surprisingly Jeter has actually done better going on, avg 200 per year since. My money's on him finishing the highest of the 3.

Rodriguez because he keeps playing to get all the all-time records, although I've heard Jeter rumblings about him having a shot at Pete Rose (the long and short of it - he does if he plays forever like Rose did), so he might try it too. That would be possibly the most unlikely baseball record race of all-time, by the way, if both were trying to break the all-time hits record at the same time in 8-10 years. 5 guys have held the record, only three starting with Cap Anson.

Ken Griffey, BTW, is a rare bird as an active hits leader in that he has no shot (apparently) at 3000 hits. The last active leader to not make it to 3000 was Bill Buckner in the late 1980's.  Jeter will of course be taking over this crown in the first month, barring injuries.