Cutting edge is always jenky. I personally figure Apple basically kicks back while other people develop and test, and then they release once it's been tried and sorted a bit so they don't have to release jenky products.
If you really believe Apple spent 2 years developing and perfecting cut&paste you are crazy. They waited until they wanted to implement it. What their cue was, I don't know, but I have my suspicions.
I doubt Apple "waits", they prefer to limit them-self to a focussed feature set "done right". Apparently - the entire iPhone 1st gen was designed and developed by a very very small team. This helps consistency, and avoids having some parts of the team not knowing what another part is doing. If they then - like they did for the iPhone - start with a clean API and environment with future expandability in mind, you start out with a solid architecture on which they can build. The downside however is that the initial product has a very small/basic feature-set. Upside is, its core features are (mostly) "done right" and behave consistently. A ton of features, which the competition already has, are missing, but nobody uses them there because of complexity or weird behavior.
Copy-paste is actually a perfect example here. I have had many smartphones and PDAs (iPaq, Nokia communicator, Sony-Ericsson P910, P990 and a few others) - and in none of them I actually ever used the copy-paste (if it was there), or at least certainly not as much as I do now on my iPhone. Worst clipboard implementation I've ever seen was that when I copied text in a one application, apparently it was placed on the clipboard as UTF8 or Ansi text. No problem so far - but apparently, if your target app then only accepted ascii text - too bad, no copy-paste. Try explaining that-one to a normal user, good luck... I then prefer the focussed on core-features, "no clipboard" approach instead of a confusing, non-working or unreliable feature you end up not using at all.
Now I'm not an Apple fanboy, but I do have an iPhone (only Apple product I own). I'll be the last to say that it's perfect and everything is entirely "done right", but from what I've seen - from a user-point of view - it's without a doubt the best thing out-there. Yes there are on paper "better phones" with "more features" which are "more open", but whatever, it just works. On PC I might be considered a power-user, but my phone is a vital part of my life. I don't want to mess around on it too much - it has to simply work. I did consider buying an Android phone for the sole purpose of playing with it, but I simply don't have the time for that at the moment. I might still do this in the future, after having played with 1.5, 1.6, 2.1 and 2.2 on various models of friends - I have to say, I'm impressed by the technical improvements, but still - the user-experience is just horrible. There are some cool ideas, like the notifications - but the execution is mind-blowing irritating after a while. It feels to me as a linux desktop 10 years ago: editing your config file with vi is easy. Designed by an engineer, for an engineer.
If you really believe Apple spent 2 years developing and perfecting cut&paste you are crazy. They waited until they wanted to implement it. What their cue was, I don't know, but I have my suspicions.