Shannon, I agree that an enterprise, by creating value over time, should be more than a "zero sum" game, but this is by no-means guaranteed.
More importantly what, exactly, is value?
Personally, apart from 'assests' (e.g. land, property, machinery), I think all the things you happened to mention (i.e money, intellectual property, brand etc.) are, in reality, virtually totally value-less.
I would argue that increased community well-being (as defined by members of the community) can be the only true measure of real value.
However, most governments and businesses today take what It an extremely short-sighted, closed-minded and fundamentally incorrect view: that economic growth = improved well-being.
This is simply not true.
In fact, as economists such as Herman Daly (formerly of the World Bank) and Richard Douthwaite have shown, many Western Economies (the US and UK included) have actually been running in reverse for that last few decades (i.e. the increased economic growth they have experience over these years - as measured by GDP - has actually decreased well-being).
Two very good books on this are Beyond Growth (Herman Daly) and The Growth Illusion (Richard Douthwaite).
A good NGO working towards solutions to the economic growth short-sightedness is Redefining Progress
The reason why $10 buys a different amount now than it did 20 years ago, is because the current interest-bearing debt-based money system is inherently unstable. Even the historically most stable currency in the world (DM by the way) has lost about 50% of its value since WWII.
Similarly, in line with what Daly and Douthwaite suggest, the value of labour in the US has actually gone down so that an average US worker now earns less than 30 years ago! (see shared capitalism institute)
Like blogs, wiki and indymedia have reinvented and democratised media creation and distribution, new accounting systems are urgently needed to reinvent and democratise money creation.
The best reading about this can be found via reinventingmoney.com