This is such a great question. In my opinion, technology is moving so fast, it's really too hard to speculate. Things are obsolete in a month....new DAW's are coming out every year....you just never know what will happen next. I can tell you this as I beta test for quite a few companies....the next two years are going to blow your mind with what will be available DAW wise. People that are not known for recording programs are testing them as I type this...and let me tell you, some of them are sick!
Studio 1 for example, broke the scene with a pretty solid DAW in my opinion. Graphically, it's nothing to look at and needs some work, but function/stability wise, it's been really great for me. Sequoia has been solid for me, Reaper has been solid for me, the latest PT and Logic have been solid for me and of course so has Sonar which is still my personal preference. Keep in mind, all have bugs...but none have show stoppers where they are so broke, I can't do my work.
I think what we need to look at (which is pretty impossible due to all the variables) is how a majority is using a particular DAW. What makes PT so right for most of the major studios to where everyone had mentioned it still being around in 7 years? It crashes too. However, running it on a well-built MAC in my opinion, obliterates any Windows and PT relationship. If you use PT, go MAC. Sure they can have problems too...but we haven't had to touch anything with both MAC's we have. PT on Windows....very unpredictable.
Anyway, I agree with what someone said about "having a user base". My point is....if a DAW fits a particular group of people, it should survive. It's like owning a studio today in a time where studio's are dropping like mad. You have to deliver something that no one else has. You have to do it in a timely fashion and you need to be trusted to the point of never letting a client down. Selling service is important even if you aren't the best engineer. If you can do something better and faster than someone trying to rough it buying a recording program from Sam Ash and you charge a fair price, you win. I think the same can be said about the DAW market. Do things the others can't and do them well. Do things the others do, but do them better.
At any rate, my final thoughts are, the winners in 7 years will be the ones that work with MS and evolve as they do as well as borrow the best features from the competition. The winners will market and advertise that it matters not what DAW you use to create hit music. It's time to debunk the PT myth. Someone should approach a famous engineer and ask them....
"Here is a copy of our latest and greatest DAW. Please try it. If you don't like it, tell us why you wouldn't use it?" All it takes is for a few known engineers/artists to have a few major hits while using a DAW that isn't PT. Let someone that IS someone tell us what is wrong with our DAW.
At the end of the day, who knows what we'll be doing in 7 years. The way things are moving so fast....we may not even be using DAW software to record music like we are today.
-Danny