In the current batch of updates, Windows Update offers an app which puts a Windows icon in the system tray. When you open it, it presents you with a chance to reserve a spot in the que to download Windows 10 when it becomes available on July 29th. Installation files are downloaded automatically, but the installation is run manually. For early adopters, I guess this gets you a priority slot in whatever bandwidth MS will make available to the download. More here.
I think I am going to back up my drive on my laptop and take this for a spin. The worst that could happen is I format and start over.
"But I got it because I'm an iSheep who needs to have all my stuff have an Apple logo on it."