I have to chuckle a little bit as I read this thread.
There are very few leagues where Laroche won't be worth a roster spot if he's playing every day, and there are even fewer keeper leagues where I'd hesitate for even a second before grabbing him.
This is a guy who was a consensus top 20 minor leaguer before the season started and rated even higher than Ryan Braun by Baseball America and a bunch of other sites/people.
It's entirely possible that he struggles like many young players do, but a slow start at AAA shouldn't turn anyone off. In 202 AAA at bats in 2006, he batted .322-.400-.550 with 10 HRs and 3 SBs. He also walked 25 times compared to 32 strikeouts. Something tells me that if he had started off hot this year, he'd be looked at differently... that's just silly.
Especially in keeper leagues, go get him if you can.