Get people used to the ubiquity interface regardless whether they begin the process with a mouse or keyboard. This maintains consistency and you only have one interface to receive feedback and work on.

So for mouse navigation, this is how I’d see it working : when you select text, the selected text flies (think maximizing window like effect) and becomes part of the normal ubiquity interface (just like you had made the selection and pressed the activation keys).

The difference is that now, a user only has to move the cursor over the action (say “email”) and rotate the scroll wheel for it to change to other alternatives. Maybe have an animation here too…like an old petrol pump…or something that makes it obvious that it is the motion of the scroll wheel that’s causing the change.

In addition, since it is mouse only, words like “to” will have to appear automatically (for example, in “email to”.

Finally, using the same example of emailing text to a contact, the user will be able to use the scroll wheel to move over the alternatives. If there are a lot of alternatives, like in email contacts, group them (there are several possibilities, but one obvious one would be by first inital…an index tab of sorts above the current contact.

This lets everyone get used to and improve on one interface, which is a good thing from the start. This will also be good from a touch screen point of view – using ubiquity on a smartphone or internet tablet, for example.

From my experience, people who use a mouse a lot, like to know what effect their clicks and scrolls are having. This is why it is important to show them whats going on.