He will obviously cool down. Here's some of his numbers and the approximate MLB average:
LD% - Ludwick 39%, MLB 18%
BABIP - Ludwick 44%, MLB 30%
HR/FB - Ludwick 29%, MLB 12% (this one varies the most, since hitters w/ more power like Howard can routinely get it up to 18-20%...but NOT 30%)
It's actually absurd what Ludwick has managed to do thus far. He's hitting only 20% of balls on the ground, compared to most guys who are like 35-45%, and almost all those balls that he's getting into the air he is actually hitting right on the button (hence 40% line drives) and sending them out of the park. The ones that don't are falling in the gaps about 1.5X as often as the average hitter, as his 44% BABIP shows (of course, BABIP is correlated to line drives, so the reason it's so high is that every ball he hits, he's scorching).
Be skeptical- he hit .267 but he's still striking out 25% of the time and has a bad K:BB ratio of roughly 3:1. He's the same hitter as last year, he's just on a really really hot streak.