Here's an intriguing little change — today's Google Search app update, which carries an unassuming changelog of performance improvements and fixes, actually brings new branding for the Nexus 5's home screen launcher. (Parts of the launcher are contained in the search app itself, since that's now Google Search works on the N5.)
After updating to the new Search app, the name of the Nexus 5's launcher in the Settings > Home menu changes to "Google Now Launcher." Some other devices with the Nexus 5 launcher sideloaded are also seeing a new "Google Now Launcher" splash screen when the app is first updated, which we've dutifully captured for you after the break.
Make of that what you will. It's possible this is a precursor to a wider rollout of Google's launcher on the Play Store, as many have predicted. It's also possible they just decided to change the name, so let's not get too excited just yet.
Update: Looks like if you sideload the Google Now Launcher APK onto a device with the stock Android launcher, you now get the option to import app icons across to the new launcher. That's another possible sign that Google's launcher will be spun out onto the Play Store at some point. We've got pics after the break.