Hi Oliver:
We think is very practical for Mobile Devices. One thing that is of particular interest to us is for the most part the universality of a widget created based on canvas. You are more or less guaranteed it'll look the same in any desktop/mobile or any device for that matter implementing the canvas spec. Something that was once a dream for many using webkit but due to the current fragmentation, it has become harder to achieve.
In this case for static "views", a canvas it's nothing but a bunch of pixels drawn on the screen which is out of the box resolution independent. So compare that to building complex DOM structures in the browser and there is already a gained benefit. When it comes to animations for example, the way things are done is pretty efficient I have to say. An animation is typically wrapped in a requestAnimationFrame (
http://google-web-toolkit.googlecode.com/svn/javadoc/2.4/com/google/gwt/animation/client/AnimationScheduler.html). This is a rather efficient operation since it allows the browser to realize the animation in the most efficient way. Very important since it allows the browser to trigger the next animation step when it needs to. Something interesting in this area is how the actual implementation works. If you go to a different tab, navigate away from the view, etc... all the animations are suspended. That by itself will automatically save CPU cycles, battery and resources. Also the sort of animations that we can now create are not bound the the ones provided by browsers. We can animate anything we want to in previously unimaginable ways.
Lienzo 1.0 supports most the core functionality that will be needed to build things on top for Mobile or Desktop. That is, we support dragging in a mobile device, events, etc... Things such as scrolling, scaling and others are likely to be created and added as another library that will seat on top of it. More of a widget library at that point. Hard to draw the line but as of now that's the idea. Doesn't mean they won't get added to Lienzo directly in the near future.
Help is something that we really, really need. More so when it comes to creating test cases, analyzing performance, battery on mobile devices, CPU utilization, you name it. We have made Lienzo very extensible so creating widgets or modules on top of it should be very easy. Creating a chart library, widgets and other cool things. We have created some examples for possible widgets such as Sliders, Progress Bars, Toggle Buttons and we were ourselves surprised to realize how simple it was to do so. And they are slick. Since you have total control over shadows, gradients, I mean you can pretty much do whatever you want. So yes, please by all means if you have some time and can give it a try and see if you can come up with some tests, etc... it would be really, really cool.
Man sorry for the long email :( didn't mean for it to be this long.
Really appreciate the feedback/questions/ideas and we look forward to a lot more so we can improve things and make them better for all.