You could go play another sport, teach yourself some additional physical skills (some of which would help in baseball) and avoid the overuse problems the medics are warning about.
Since this site is geared to the preteen player I would say these camps are a waste of money. You will get little or no individual attention. All you would be doing is helping finance their preconference road trip.
Disagree, mostly. The best winter camps around here are run by the local JC, where the coach is great and runs a very successful program. My kids have taken his summer camp a couple times, and he has most of his team working the camp, so the kids are getting a lot of individual instruction, and the JC players are getting a good taste of their most likely future role in baseball. As for being a waste of money - no way. Camps are usually tax deductible daycare that is less expensive than other daycare options.
That said, I wouldn't have my player doing a winter camp. Nobody in my house has picked up a baseball since mid-October and they won't be throwing until mid-January.