The shift to WebKit means more of our resources can be dedicated to developing new features and the user-friendly solutions that can be expected from a company that invented so many of the features that are today being used by everyone in the browser industry.
This is a smart move. Improving the experience of the browser should always be the main goal of any browser developer and by not having to focus on constantly updating their own rendering engine, Opera can spend more time making their browser better. They can also help improve WebKit and as they’ve always been active in helping push the open web along, having another big name contribute to improving WebKit (like Adobe have been recently) can only be better for us all.
From a designer/front-end developer’s point of view, I think this is great. We should have far fewer problems with Opera going forward, so we can focus more on making great websites instead of testing. Although, to be honest, I’ve never designed or developed for a site where the number of Opera users was large enough to be concerned about.
If all browser used and contributed to WebKit, we as designers and developers could spend more time focused on creating great websites as it would cut down on the amount of testing we would have to do. I don’t expect any Microsoft or Mozilla to move over to WebKit but then again, I didn’t expect Opera too either.