Google Wave's default user interface looks much like email, with three panels: a list of menus on the left, list of messages in the middle and contents from selected items on the right. One problem I am having is that Google Wave is a bit slow. I thought this might be because I am using a slow wireless Internet connection, but the team suggests it might be due to problems with Firefox 3.0 (later versions work better). However, I suspect my Virgin 3G wireless the interface, which is working at about 64kbps, is too slow to be usable.
However, another is is that Wave is very dynamic. Unlike email, blogs and even twitter, the Waves change dynamically as participants (and robots) enter change and change content. As a result there is data being transmitted continually to the client (this may cause problems on slow and expensive links).
Also as a result there is continual movement on the screen. As a result I am having difficulty in following what is happening. While looking at something it can suddenly move. Even while typing this in Blogger, I can see the title of the Wave tab in the browser flickering, which is very annoying.
The Wave team need to provide a way to smooth the interface so it does not change to abruptly and even a way to have it happen in steps on request. An interface which shows gradual movement, so the user can see it happening, rather than making sudden jumps could be useful. This might also avoid make slow links more acceptable and also avoid photosensitive epilepsy seizures.
There could also be some interesting issues with the accessibility of the interface for people with a disability. The interface is respecting the minimum font size set by the web browser, allowing me to make the text large enough to read. However, there are so many images and columns used that the text is too narrow to be read.
Exactly how to interface to accessibility devices with Wave would be an interesting issue. This area of work might be usefully combined with interfaces for netbooks and smart phones, with small screens.