That's the very question I ask to myself everyday for my pilot career.
I don't even know if in 10 or 15 years fuel won't be so expensive it will make most airlines disappear in a few years (in 2008, many low costs including the one I'm maybe joining were close to disappear, the price of the petrol barrol stopped 1 or 2$ before it was too late, because measures were taken in order to avoid that cause it would have got even worse, that's a part of the explanation why it had finally stopped increasing).
I'm not sure I will do a total career without having a major problem. Of course, the bilan will be positive since a pilot is very well paid, but still, my 40 years career is compromized. What makes my future brighter is that manufacturers still research and design planes, make them more and more efficient and awesome, and since it takes 10 to 20 years to make a plane viable, this is hope for at least 50 to 100 years of flying the way we know it.
That's why I plan in my life to have several possibilities at the same time, at least enough to live, and if possible in things time doesn't change too much.
Concerning audio production, in 30 years... well, I wanna play the devil's advocate here, just to think a little more. First, one thing is easy to do : exagerating the acceleration of development because it's something very natural. I mean, to talk about something I know well, 100 years ago, people were betting we would all have flying cars. And if we think about it, planes are almost the same now as what they were let's say 70/80 years ago.
Same about cars. They have improved, but in essence, they are still the same thing.
So it's too easy to think in 30 years a mix will do itself by a computer and will sound good. Okay, computers are another deal, they double their power every 1.5 years statistically and have the particularity to be able to do virtually almost everything, granted a human being makes it do it.
In 10 years, many things can change, but not "drastically" either. In 10 years, we will have certainly better sounding emulations, maybe better sounding amp cabs. Since when I started recording myself, there has been improvement but it hasn't changed totally in those 5 years. Waves SSL is older than 5years, isn't it ? So by then we'll have better sounding emulations, maybe a new distribution of the DAW market. Maybe protools will have lost its supriority in most studios, maybe the contrary.
In 20 years, now that's difficult to predict. At least 1 to 2 generations of audio interfaces. Maybe a little improvement in the microphone market but that seems a market where improvement is less obvious.
In 30 years, it will have changed a lot. I guess the concept of stuff like EzMix will be more used. If it works, why not ? There will still be a need for trained ear and experienced folks to put their hands in the project, but it's not too hard to bet it will be even easier for a bedroom warrior to do something decent out of a piece of software.
We also have to imagine maybe by then, some of our basic concepts will have changed, and the way we mix today will look "old fashionned" but maybe will still exist, exactly how we (most of us) do when we see a full console mixing tapes to another tape.
I'm more worried for the next generation, not only in engineering but in other fields. I'm not worried for the fact they'll have less work, but only because my cultural vision of art, work, society, is against the fact it changes.
Whatever happens, we have to deal with it.
The most important thing is to be clever about it and to make it an advantage. So it's maybe more intelligent to avoid spending more in gear if one is not able to make a good benefit out of it. To make a GOOD use of those new technologies. And never leave the train and be like an elder saying how better it was before, and do nothing about it, thinking he is fighting with a good morale or dunno what. He "maybe" is right, but maybe it's a dumb idea.
Also, those things will ever stay relative and subjective. I've heard an interview 2 days ago where a musician told he thought that since the 30's the audio quality has only decreased, even the 70's for him were crap, sonically.
[EDIT : I experienced a BSOD but hopefully firefox reminded my post... phew, I have to track that driver which is said to be faulty, it's driving me nuts]