Looking at this Gartner study teaser...

Gartner Says Worldwide Mobile Phone Sales Declined 8.6 Per Cent and Smartphones Grew 12.7 Per Cent in First Quarter of 2009

...can be viewed two ways:

1. The mobile phone world is doomed with a sales drop of 8.6%
2. The mobile phone world is leaving the feature phone era and entering the smartphone epoch

But, I think there's a third interpretation:

Like feature phones, desktop PCs and notebooks are also dropping in sales and marketshare. So...

3. The world is converging on smart connected devices like smartphones and netbooks that are both small and affordable. And, both smartphones and netbooks are in the $200 to $400 consumer sweet spot of affordability.

There will always be people and tasks that require powerful desktops and notebooks. But, it is clear that the combination of the current poor state of the economy and people's desire to be on the move give smartphones and netbooks a leg up on their feature challenged (feature phones) and weight/size challenged (notebooks) predecessors.