Now, smaller but important bits are getting revealed about Windows Phone 8.1. So, one of the annoyance with Windows Phone 8 gets resolved with ability to search messages coming with Windows Phone 8.1. So, as per the screenshot shared above, as soon as you start typing in messaging search, messages with those letters and words show up. This has been on other platforms for ages and even on Windows Mobile the predecessor to Windows Phone. Though, now with universal search support and Cortana, search on Windows Phone may look better than ever.
Another important bit is about new Music app on Windows Phone 8.1, which is actually Xbox Music app built in the OS now. According to Joe Belfiore, the new Music app will be able to get updated via Windows Phone store, making improvements more frequent.
@wiiggin yep. The Music (aka Xbox music) app built into 8.1 is much improved. And store-updateable.
— joebelfiore (@joebelfiore) April 7, 2014