The brief change notes for the apps state, "You can now ask Cortana 'Shazam this' to instantly start identifying music around you. We've also improved performance and fixed a few bugs." The update applies to both the free, ad-supported, Shazam app as well as the $5.99 ad free version, Shazam Encore.
Do you like that more Windows Phone apps are adding Cortana support? Thanks to everyone who tipped us!