Many reviewers have noted the loudness as well. "To me it’s of a piece with the clicky feel of the new keyboard, which I like," writes Daring Fireball's John Gruber. "The premium clickiness is what made me say in my review that it’s a mixed bag, not a complete regression from the old ones. People who work in quiet rooms might disagree."
Gizmodo's Christina Warren wrote, "I’ve used three different MacBook Pro models over the last few weeks and honestly, [the new MacBook Pro] probably is a smidge louder. The new MacBook Pro’s keys have less travel than its predecessors, and that could be why pressing down on the keys makes more noise... it’s not that big of a deal."
It appears that there's plenty of evidence that the new laptops are a little more "clicky," but Warren kind of nails it. It's probably not worth getting worked up over.