Well, take this with a heavy dose of salt!! Two images are doing rounds and are claimed to feature new Windows Mobile 10 home screen and app list. The noticeable difference from Windows Phone 8.1 home screen is in the background image appearing all over the display (In Windows Phone 8.1, it is limited to tiles) and even in the app list.
While, we have heard about Windows 10 phone version to bring more home-screen customizations than Windows Phone 8.1, we are not sure it will look like this. We tried to check it on Fotoforensics.com and the image ELA analysis doesn’t inspire confidence for it to be the real deal. We are not experts though and may interpret it incorrectly too.
So, if it is not real, treat it as a concept and do let us know if you would like your Windows Phone home-screens to look like this.
Thanks @techlumia925 for the tip. Cheers!!