I think Apple had quite a tough job to do here, with people ready to pounce no matter what. If they didn't refresh enough then cries of "same old, same old"; if they radicalised it too much then even ardent fans might turn; and I think if we give credit where credit is due (and I don't hand out credit to Apple willy nilly!), they've actually done a decent job.
They may have "borrowed" a couple of design cues from Android (I think I read about "slide to archive" being introduced in the Mail app... sound familiar?), but in fairness you could easily see that as a quid pro quo for some of the Apple design cues borrowed in earlier editions of Android.
With regard to the look, I think as all three main mobile OSes have tried to modernise they are clearly working within current design hints and trends, and whilst they all have their unique takes on them (Holo, tiles, whatever), they will have similarities and "feel" similar in some ways because that's what modern design dictates. Only a few years ago, the trend was for blocky, 3D images and icons, heavy use of gradients, embossed buttons and lettering, shadows here there and everywhere and a general spattering of "depth" all over. Think of the old, heavily embossed and shadowed "Google" logo and that Xara 3D program everyone used to use to create website headers. iOS and early Android reflected this.
Fast-forward to now and the trend is for large, sleek, flat images; bold and consistent (and also flat) colours, thin lines, iconic over skeuomorphic, light fonts, etc. Android adopted a lot of this with ICS, Windows Phone 8 has - despite the other criticisms people may lay at it - always had this, and now iOS is adapting it too. They are all following the same design hints, in order to fit with the current vogue - I don't think this necessarily means they look "the same".