Aaron or A-rod?

Will the current home run leader surpass hank Aaron’s record for total home runs? Will he be able to keep hitting home runs at this rate? The real question is exactly how long will he be able to play baseball at the competitive level? Right now Alex Rodriguez is tied for 50th place on the all-time home run list. But , he is only 30 years old and still getting better. Hank Aaron hit 755 home runs through his 23 years in the majors(A-Rod has 381 while in his 12 season). Aaron retired at the age of 42. Right the oldest players in the league are just about at 40. So by the time A-Rod is 42 will he be watching baseball from his recliner (just shy of Aaron) or sealing his place in the Hall of Fame?

http://sports.espn.go.com/mlbhist/alltime/leaders?breakdown=2&type=0&sort=8&year=0