Qt 5.0 has been a long time coming and then in recent weeks there was the fumble with Nokia selling off Qt and making other changes. Qt 5.0 Beta was originally supposed to come earlier this summer, then delayed to early August, and now it's arrived at the end of August.
For those unfamiliar with the changes made to Qt 5.0, see the feature overview. There's lots of good stuff in Qt 5.0 from improved graphics performance to new API functionality and other new components. Qt 5.0 has been under development for about the past 15 months.
For more information on today's Qt 5.0 beta release, see this blog post by Lars Knoll.