I agree with the socialism comment, although comparing it to socialism may be a bit extreme.
Open Source is an excellent idea and I, personally, look for open source programs to replace the programs I have paid for. I like the idea that the program was made by the users more than it was the owners, and thus making it better. This theory does not always line up with what really happens, but it is true enough that I give open source programs a try.
However, for certain things, such as imagery and graphics, there are programs that dominate the field because they are better. Overpriced programs, like Photoshop, are overpriced for that exact reason - they're better, people will buy it...
Now, to look into the future and guess upon whether or not open source will be the main thing...well, on that subject I really cannot say. There will always be open source and there will always be programs like Photoshop. Both sides will have ups and downs depending on many different factors. I guess we'll see have to wait around and see, wont we?