Every year since 1986, the Mercury News has published a list of the largest public companies in Silicon Valley, now known as the SV150. It’s a big undertaking, and one that I always find fascinating. This year, as I wrote in my column for the SV150, we expanded the definition of Silicon Valley to capture a number of new companies, and to recognize the fact that there is a lot of startup momentum in San Francisco and the East Bay.

But there were several other themes that struck me from reading the section this weekend:

1. The big headline f0r me came on Brandon Bailey’s story about Apple knocking Hewlett Packard off the top spot for the first time since we started publishing the list. It’s something I never expected to happen, seeing HP fall from number 1, and it marks an interesting constrast. HP built an enormous lead over the past decade by spending billions acquiring other companies, starting with Compaq. And then it goosed profits by firing thousands of employees. Great short-term strategy, but one that appears to have faltered and stagnated in recent years. By contrast, Apple grew by creativity and innovation. They did it to a degree that seemed inconceivable a decade ago. But the results are undeniable, and it appears to have positioned them much better for the long haul.

2. While we know Apple has been on a tear, the numbers in that story still blew me away:

“Essentially, Apple accounted for $1 of every $5 in sales reported by the SV150 as a whole, and nearly $1 of every $3 in combined SV150 profit. And as its stock price blew past $600 a share in March, Apple ended last month with a market capitalization of $558 billion. That was nearly a third of the market cap for the combined SV150.”

This company is leaving everyone in Silicon Valley in the dust.

3. As the story notes, beyond Apple, it was a very mixed year for Silicon Valley:

“While combined sales for the valley’s 150 biggest public companies rose 17.5 percent last year, one in four of those companies saw their revenue fall in 2011. By contrast, only one in eight companies reported sales declines in 2010, when tech spending came roaring back from the recent recession.

And while the SV150′s combined profit rose 22 percent last year, almost half the companies on the list reported a profit decline. That’s nearly three times the number reporting profit declines in 2010.”

We keep talking about how tech is leading the economic recovery around here. But really, that growth is being driven by a minority of uber-successful companies and what appears to a big startup boom. Companies in the middle are still struggling.

4. Facebook, when it goes public, will debut high on the list next year. According to Pete Delevett’s story, Facebook would have been no. 26 this year. Given its 85 percent growth rate, it should crack the top 20 next year.

If you haven’t read the section, check it out. Curious to know what jumps out and surprises you?