Last month we saw Ajax was making a move to the desktop with the aid of Adobe Apollo. Earlier this month I talked about it again when Sun announced JavaFX and after  Microsoft officially announced Silverlight.
I guess it was inevitable that Google would also join the fun of blurring the lines between desktop applications and web applications. And indeed I just read that Google released a beta of Google Gears.

What does Google Gears do? well, in essence it lets you develop occasionally disconnected web applications by providing an API to store application resources and data locally as well as Workerpools  that allow you to run tasks in the background (sort of like a collection of processes that host javascripts and  can communicate by messages).

What all these means is that it wouldn't be too long before the the architectural choice between web clients or desktop clients will not be that important it will be more about making a technology choice on the  preferred development environment and tooling as well as designing robust occasionally disconnected applications regardless of that technology. Just look at  the architectural guidance Google provides for utilizing Google gear.  You'd see that the components that they identify are very similar to the high-level components you are likely to design with any occasionally disconnected desktop application...