- The growing improvement in the quality of online applications

- The rise of the smart phone

The biggest factor is cost. Microsoft wants consumers to shell out between $140 and $600 for Office and between $155 and $380 for Windows Vista. The antimalware companies are bleeding consumers dry with pricing for Internet security suite subscriptions. All this software is super expensive, and requires ever-more expensive hardware.

It doesn't take a rocket surgeon to figure out that you can just buy a cheap PC and run apps online -- and save your money for new mobile gadgets and other consumer electronics hardware. Plus, online applications enable you to access all your personal stuff from work.

That wasn't really feasible a few years ago, but now the selection and quality of browser-based applications make it possible to do everything online. Google's offerings alone are sufficient to replace Outlook for most consumers: Calendar, Docs & Spreadsheets, Gmail and Picasa provide most of the basic functionality of Office. We'll also see this year a host of innovative browser-based apps from start-ups, such as the highly anticipated Scrybe calendar and task manager.