I say yes for sure. I preferred Stanton to Hamilton preseason and even though he may miss the next month or so, I think he ends up with better numbers than Hamilton at the end of the year. Hamilton's age, strikeout rate, and move to Anaheim are all reasons he won't return to his elite numbers of 2010 and 2012, so even if he does turn it around I'm not expecting him to have the power he used to. Also, remember that Hamilton is a huge injury risk as well so it's not as if he may not hit the DL this year at some point either. At this point, I would definitely do this deal.
That being said, there may be some safer, healthy guys that you can trade Hamilton for rather than Stanton. Stanton certainly has higher upside than anyone else that you would trade for, but there may be some other slow-starting second-third round type guys that you can swap Hamilton for. Without seeing your team, knowing your league size / categories, etc it's hard to say, but swapping Hamilton for a guy like David Price or Matt Cain would be a good trade also if you are hurting in the pitching categories.
Help with mine? viewtopic.php?f=26&t=460201