Much has been written about the good and bad of skeuomorphism. Tom Hobbs wrote a great piece putting everything together.
Digitally re-creating real materials and analog objects very quickly becomes aesthetics for aesthetics sake. It’s hard to believe that all but a minute percentage of Apple’s user base has a tan-suede–bound calendar or book of any sort, or anything else that looks remotely similar. Unfortunately, these are the characteristics of skeuomorphism that a vast majority of UI designers employ when they use this approach (see Blackberry’s Playbook). Ultimately, it encourages designers to become less critical and less inventive, which is detrimental to evolving new and improved solutions.
He argues skeuomorphism hinders designers in creating something truly innovative. Also, some good arguments on why Microsoft’s Metro interface isn’t the answer:
Sure, these graphic elements don’t use “superfluous” drop shadows and renderings, but they don’t really use space any more efficiently than many skeuomorphic iPhone apps. It is highly debatable whether they need to be as graphically dominant or whether the aesthetic form is purely driven by function. Metro’s graphic elements are largely abstracted representations of their function, so from a modernist point of view, it is interesting to think of what else could be stripped away to enhance their function.