First off, we recommend turning your light on and off continuously throughout the above YouTube video. Extra bass helps too. Anyway, the above demo is of Sliding Keyboard for Windows Phone 7, version 1.8. We recently covered the app at verson 1.7, a day before the update was submitted.
What's changed? The major improvement is speed of rendering text after you've swiped your heart out on-screen. Smaller relevant dictionaries, better localization support (with multiple keyboard layouts) and an option to translate text has been thrown in.
You can download Sliding Keyboard from the Marketplace for 79p ($.99). For those who already use the app, keep an eye out for an available update.