First of all, this looks like this only works when you are in LaunchPad mode so there, it makes perfect sense. I truly doubt the press/hold/jiggle works in the Applications folder, where it would be very out-of-place.
Imagine that Apple did not put in the feature there in LaunchPad which is suppose to be iPad-like... people would come out of the woodwork to piss/moan about how Apple was lame to not unify the process with the press/hold/jiggle.
Secondly, this only works for Apps that have been downloaded from the App store,... this is probably implemented so that when you say YES, delete this, it will then give you an option to rate the App while simply deleting the App with a Command-Delete or a drag to the Trash would not invoke such a Rating option.
Thirdly, it's not like Apple is taking away the other options of trashing an App. Use the method that you're like and MYOB and STHU. Honestly.
50% of Mac buyers are new users so they're use to this from iPhones/iPads/iPods. Let them be comfortable. I've been on a Mac since 1995 but I realize that Apple needs to help switchers be comfortable. All the changes to Mac OS X that I've seen so far, I'm really looking forward. If you don't want 'em. Don't upgrade. Oh... and STHU.