I've noticed a general decline. "Kids today" (though I'm only 24) seem to be even worse than we were. Perhaps it is just that I notice different things, now, compared to when I was a kid (or I'm just more aware of what goes on outside of my own little bubble).
I think a lot of it, however, has to do with a difference in parenting. Far more parents these days are single parents with multiple kids. I've never seen this work out to be what one would call healthy. In most cases, the kids basically raise themselves with little in the way of adult supervision or role models.
Worse - it's a self-feeding cycle. Teen pregnancy is exponentially higher among those raised by a single parent (and most of those pregnancies go on to be births under a single mother with little in the way of financial stability). Behavioral disorders, criminal activity, etc are all much higher among these groups due, in large part, to the disruption of proper parenting.
I am a believer that, if something isn't done within the next two to three generations, our society will be completely over-run with babies making babies (fed by welfare programs, of course). Obviously, the efforts we are making are not fixing the problem (in most cases, all they do is enable it to continue).
Compare it to how things were for my parents (and how my parents raised me): My parents expected to know where I was any given moment of the day; deviance from that expectation was met with consequence. I did not tell my parents where I was going - I requested to go there (unless it was in our own yard); my parents would have corrected me if I showed that there was confusion as to where I stood in the decision making process. I was to ask my parents for permission to invite friends over. Hell would have been paid if there was someone in the house that had not been cleared to be there by my parents. Until I reached a certain age - my parents screened the movies I was to watch. When they felt I was mature enough to handle a movie - they let me see it (I don't recall them screening movies past the age of about ten for me - but the fact remains that they took the time to pay attention to how I reacted to the content of movies).
Now - my parents were pretty easy going, and they rarely turned down a request for me to go and do something. But it was still understood - they were in charge, and I was accountable to them.
A lot of the above is pretty basic stuff... but as I've gotten older, I've noticed that these principles are lacking in a disturbing number of house-holds (often the single-parent households by virtue of the parent being at one of two jobs most of the time... but there are also a fair number from parents who want to try and be their child's best friend or something along those lines). People come in and out of the house on a regular basis (often without the knowledge of the parent... or the parent has given up trying to control access to the house). Kids call from 45 miles down the highway that they need a ride because their 'friends' left without them (been on a couple "Operation go get dumbass" missions at 2 in the morning...). The list of atrocities goes on.
I picked up on a lot of things from my parents that they didn't necessarily "sit down and teach" me. When I spoke, they listened to me and paid attention to what I had to say. Didn't mean I got my way all the time - but I wasn't shot down at the word: "Mom!" My parents never disciplined me without explanation, either (my dad was the king of lectures... and, obviously, that imprinted upon me) - I always knew exactly why I was being sent to my room without dinner, or had the TV taken away. I also saw how my parents treated each other. If they had arguments, they were irregular and never in front of us kids. My mom never hit my dad, or vice-versa - even as a playful thing (it wasn't their nature to play that way). And they genuinely showed that they loved and cared for each other by being supportive to each other and to us kids.
I grew up knowing what a clean room was (even though I was rarely the cause of it), with the expectation that the entire family would sit down to a meal at the same time and same place (something that took me a while to get over when I moved in with my room mates and I kind of had this weird expectation that we'd all sit down and eat together - wasn't something they grew up with and they didn't quite get why it was a deal to me), and with an imprinted instinct to be supportive to people around me (in spite of a somewhat vindictive and brooding nature).
So... I'm talking in circles at this point...
I just find it hard to blame the kids for being less controlled and respectful. They, and often their parents, are largely the victims of a cycle that has been running for far too long. Sure - some people are 'born' a dirt-bag and no amount of parenting will straighten them out... but it would be foolish to disregard the relationship between lack of parenting and poor childhood development.