Today, Mary Meeker gave her annual data dump of key Internet trends at the Web 2.0 Summit in San Francisco. As always it was fairly rich, including lots of mobile usage data as leading indicators for opportunities in content and ad delivery.

One of the more notable slides included global smartphone shipments plotted against PC (both desktop and notebook) shipments. They’re set to intersect sometime in 2012 — yes, a little over a year from now.

This prediction gains credence if you examine the trend lines and consider the fact that smartphones are cheaper and increasingly matching the capabilities of PCs. They’re also tied to the growth and ubiquity of mobile devices generally.

Also notable was the “refresh” of her staple slide that shows iOS device growth compared with other historical tech products during their respective first 20 quarters of growth. This really puts iPhone’s market influence and growth into perspective.

Drilling down further, 42 percent of global Q1 smartphone shipments were a combination of Android and iOS devices. This likewise isn’t a new story but the extent of this market share is eye opening.

More important, it is indicative of where to devote development resources for any media companies in the process of building apps (or Web sites). In terms of “picking a horse,” these platforms are clearly where usage momentum lies.

Lastly, a glimpse of the Japan mobile social networking market was provided as a leading indicator to where mobile social networking could reach in Western markets. Facebook leads this charge with 200 million regular mobile users (out of its total 500 million users).

To connect the dots with previous data points, see our coverage from Meeker’s presentation last year. You can also view her presentation from today on Scrib.d, and a few slides are below.