
The official Twitter account for Project Fi gave an update on the status of Android 5.1.1 for its Nexus 6. There, it was specified that owners of the Nexus 6 with Google's wireless service can expect to see the software update arrive “over the next few days.”
Good news! Android 5.1.1 – an even sweeter version of Android Lollipop – is coming to all Project Fi phones over the next few days.
— Project Fi (@projectfi) July 9, 2015
Don't have an invite just yet? The wait is almost over. All invites are said to be sent out by mid-summer and Project Fi currently allows you to check the status of your own invite. For me, I was told about ten days ago that my wait was 3-4 weeks but received it earlier this week. So it looks like Google has been able to get invites pushed out at an increased pace.
Source: Project Fi (Twitter)