Really tough to figure Corey out. He's always been a bit streaky, and this is a career best power surge for him. His 21% HR/FB rate is unsustainable, but the rest of his peripherals suggest he's turned a corner. In fact, his .257 BABIP (career .301) suggests he's actually been unlucky lately, at least batting average wise. He has a career-high walk rate, he actually has a positive runs above average value against the slider (a career-long nemesis), and he has the lowest out-of-zone swing % of his career. All of this matches up with the "eyeball" test...he just looks better and more comfortable at the plate.
That said, he's locked in right now...he's even hitting hard outs. He's shown this before only to come crashing down. So he may be a trade high guy (heck, I'm hoping the Brewers realize that too)...I guess it would depend on the value other people have on him. But it wouldn't kill me to hold on to him and ride him out, see where this goes. Worst case, he tanks again and you lose, what, a free agent or late pick investment?