Last week, the media headlines--and especially the tech blogs--lit up with the notion that Apple has surpassed Microsoft in terms of market cap. While undeniably a sign of the times, the actual significance of this supposed milestone remains in question. The key is to understand what market capitalization does and does not measure.

By its dictionary definition, market cap refers to the total dollar market value of a company's outstanding shares. The operative terms here are "market value" and "shares" as they signal that we are dealing with the stock market and the investment community. Market cap is a figure that investors use to determine a company's size without factoring in figures such as sales, total assets, employees, product penetration and so on.

The takeaway: we're talking Wall Street here. This is the same ilk of speculators who betted up the value of Pets.com, subprime mortgages and Dutch tulips circa 17th century.

Of course, Apple is by no means as mysterious or transient as the notorious tech flops of recent history. But it's still important to realize that the opinion of the investing community is neither an infallible nor exact science.

Still, the symbolic significance of this shift in ranks cannot and should not be ignored. Microsoft has long been a giant in the world of software and operating systems. But now, the battle is no longer pitting a David versus a Goliath. Now, it's a bit more like Godzilla versus Mothra. Apple and Microsoft are more evenly matched than ever--and that is equally as exciting as the erroneous notion that Apple has defeated Microsoft.

Apple may have won the hearts and minds of this generation, with its hip, indie-inflected advertising campaigns and it's jeans and black turtleneck corporate culture. But Microsoft isn't irrelevant yet. NetMarketShare data shows that Windows still commands 92 percent of the market share while OS X has just 5 percent. And in terms of trending, only Linux--third on the list with 1 percent--is growing in terms of market share. In the smartphone space, where the real game changing is believed to happen, iPhones and Android smartphones have supplanted Windows Mobile in terms of market share. But all three are still effortlessly outpaced by Symbian (Nokia phones) and Research in Motion (the almighty BlackBerry).

So, what does this all mean? Contrary to what the rabid Apple fanatics would like to believe, it doesn't mean that the contest is over and Apple is the winner. It means that the competition is heating up. And that's exciting for everyone.