IDC recently published a report on mobile widgets and how they may be the future of mobile Internet services. We are doing some work in that space and as such it is great to see the growing uptake and interest in the way mobile widgets may be able to help create a common platform for certain types of mobile applications.
At the moment and without the availability of a way for widgets to access things like device or network APIs, the functionality they can provide is still limited. Therefore, many people see mobile widgets as just being a way of displaying “old” Web content (or formats such as RSS) in a form factor that makes it appealing on mobile. This will change over time as more functionality becomes available.
The growing standardization on the mobile widget front (W3C and BONDI for example) should help put mobile widgets onto a wide range and variety of handsets. Add to this the fact that mobile operators are pushing widget runtimes down to handsets as they come into the market and you end up with what may be an interesting eco-system for a new breed of mobile developers.
Those people interested in building mobile widgets should for example take a look at what Vodafone are doing on their Betavine site where you can find a tutorial on building your first mobile widget. They are also holding a mobile widget competition where you can win a first prize of 20.000 GBP. Good luck!