I actually wrote a fairly detailed article back toward the end of April called Mike Lowell - Doubles Machine
. I don't buy that scouts just said his bat had slowed down to explain his performance...it's nice that Lowell wants to say that and all but I think age and possibly other issues may have contributed to a slight decline in skills.
The article covers things in good detail so I won't spend too much time writing more but basically a player that has 25-30hr power and then loses a bit of power isn't going to have all of those warning track shots get caught...some of them will find the gap for doubles. I predicted a 48 double season for Lowell based on that premise but only 8 hr's. Right now he's on track for about 10-11 hr's and about 88 doubles so other than the scale I was just about right on the doubles he's hitting.
Obviously he's not going to keep up what he's been doing recently but given what he's done so far I don't think doubles in the 50's would be out of the question (given the cushion of 16 in 103 at bats he has now). The batting average is NOT for real though. He's benifited from a 37.4% hits in play ratio which is not sustainable given his career number of just below 30%. However he is striking out a bit less than I projected (9.7% versus 12.59% of at bats) so if he can keep just that number up I could see him hitting about .285 the rest of the way instead of the .273 that I projected for him.
Edit: Just wanted to add that the problem with Lowell's value right now is his spot in the batting order. Even if he can put up 50+ doubles with 11-12 hr's and a .285 average that's only marginally valuable at second base (and not valuable at all at third base) if he's hitting 7th in the order. Even with him getting unbelievably lucky so far with hits falling in for him he still doesn't project to much over 90 runs or rbi's.
When he regressed back to a 30% hit rate on balls in play and has his average regress from the .350 it is right now back to a .285 or so that he'll get about 4/5 to 5/6 the run production he's getting now. That amounts to a 72-75 run and rbi player over 158 games played and just isn't overly valuable. If the Red Sox ignore the numbers though and just get enamored by his .350 average up to this point and he somehow finds himself hitting #2 in the order that value could skyrocket...a second baseman with low double-digit home run power, good gap doubles power, decent walk numbers and a .285 average ability would be very valuable hitting second in that Red Sox lineup.