I did some research for myself, and noticed that last year, when batting left handed (against righties), he hit a respectable .265. However, his overall average was so low because he only hit .135 against lefties (when he was batting right handed, which he's not doing anymore).
So fast forward to this year, and if you said he has been hitting solely left handed from the start of the year...notice that his average against righties is .294 and lefties .226. The vs. lefty average may even go up as the season progresses due to the fact that he will feel more and more comfortable on the left side vs. lefties than he currently does. That means that his average vs. righties will probably drop 20-30 points, but if he can keep his average against lefties to say, .220 or so, his overall average might be .250 on the season. I realize it's only a small sample size since the beginning of the season, but at least it is something worth mentioning.
If you found this confusing, sorry, there's not a very easy way to say what I needed to. Bottom line is, watch him, I think his average will be significantly higher. Good post CMB.