Minor nit: I don't think that if open source were to "win" that we would lose choice.

Though I think Microsoft's definition of "winning" would be the elimination of choice, I believe an open source "victory" would lead to leapfrogging advances and proliferation of free and non-free choices. That is, if open source "victory" is defined as a precipitous loss of Microsoft's monopoly leverage over the market.

In other words, open source need merely survive to "win." Microsoft needs to defend their monopoly power against all comers or else lose most of their value.

If they lose their monopoly power, software will become a free market, and companies can compete on the merits of their products.

Every Microsoft advance or "innovation" of the past ten or fifteen years has been in response to potential threats to their stranglehold on the desktop. The key to their successful defense of their monopoly revenue model has been their ability to retard the pace of innovation by buying-out companies, pre-announcing vaporware, and outright stealing.

The threat of open source to Microsoft is the relegation of their bigtime money-makers to commodity status. As open source versions of desktop and server operating systems, office suites and productivity apps, and development suites become more widely accepted, the marketplace will wake-up to the fact that the differences between OSS and Microsoft software cannot justify the cost of doing business with Microsoft. This is delicious irony since Microsoft pulled this stunt on competitors so many times.

My gross analogy is that once we get past having to adapt to new versions of nails (for premium prices) every couple of years, we can start concentrating on building things.

With standards-based operating systems and basic services available, the market for interoperable components should take-off. This ideal cannot even be approached these days because Microsoft artificially maintains their monopoly position by shaking-up their products every couple of years to prevent this next stage of evolution and preserve their cash cows.

Whether this nirvana can be reached is debatable, but I do believe that seeing Microsoft knocked-down from their position would go a long way toward this goal. Once the ongoing costs of adapting to the constant Microsoft shakeup is eliminated, I believe that choices would balloon. This would be for both free and non-free solutions. I think it's already happening.