Perhaps the reasons behind Hewlett Packard’s $1.2 billion purchase of Palm aren’t so obvious. I’ve seen a lot of comments like “What is HP thinking?” and “There are too many smartphone platforms, already.” But I can think of two compelling reasons for HP to buy Palm.

First, Palm has been in the gadget and smartphone business since the industry took off. It was one of the pioneers of portable information management (PIM) devices and subsequently smartphones. The Treo is arguably the breakthrough device for the modern smartphone industry. Regardless of recent performance, Palm was clearly a pioneer. As a result, its portfolio of intellectual property (eg, patents) is a valuable asset to HP now. This protects HP from patent lawsuits that can arise when devices are introduced with, say, new paradigms for navigating or computing.

Second, webOS is a powerful mobile operating system that has applicability across a great many devices. HP announced its intention to have Palm’s latest operating system power a new line of slate computing devices. Previously these were to run a version of Windows 7. With webOS’s multitasking and intuitive touch interface, these upcoming slate computers could pose a significant threat to Apple’s iPad.

There’s also speculation that HP could be planning an expanded smartphone line, and they probably will. With the Palm IP portfolio behind them, HP can confidently return to this market in a meaningful way. The mobile device industry is worth about $100 billion per year, which puts the $1.2 billion purchase price for ailing Palm into a much more positive perspective.

Personally, I’m eager to see webOS on a slate device.