Mozilla has put out a road map proposal for the next version of Ubiquity, the company's user interface project that aims to mash up user-controlled shortcuts with information from the Web. Besides the promise of an interface overhaul, the plan's big hope is to integrate Ubiquity with Mozilla's Firefox and Thunderbird products, along with user desktops.
In Firefox's case, Ubiquity integration for everyone (not just testers) could come as soon as version 3.2, due sometime next year. According to the road map specifications, the upgraded Firefox implementation would integrate Ubiquity into the "awesomebar," removing the need for users to learn a new keyboard shortcut to toggle it on and off.
The big caveat here is that any Firefox implementation would not allow third party commands for the sake of security, meaning you couldn't just start typing a new Gmail e-mail from your address bar. In such a case, users would be related to Firefox-specific shortcuts, and be required to use a separate instance of Ubiquity to take advantage of third party commands.
As for Thunderbird, Mozilla's e-mail software, the company hopes Ubiquity integration could change the way people search and manage their in-boxes. The spec says there's a need to "extend Thunderbird in ways that provide compelling advantages over Web mail." This could include things like deep integration with your system files and applications, to the point of being able to search for and add an attachment with just a few keystrokes--all without leaving the application or diving through a sea of nested folders in a pop-up menu. There's also a mention of having Ubiquity share the same set of command feed subscriptions, so if you subscribed to a new feed in either application it would be transferred over transparently in the background.
Of all of the proposed items, one that holds the most potential is integration with the user's desktop. This takes Ubiquity out of the walled garden of the browser and into user work-flow in other applications. It's the one area of the proposal with the least amount of detail, however it notes proper implementation would be in existing launcher services such as Quicksilver (for Mac) and Enso (for Windows). Presumably, when integrated with either of these, users would be able to begin to mash up items from their machine with Web services that much faster.