I am a Windows Insider but..

 I have only Nokia Icon.

Microsoft has released the 2nd Windows 10 build for phones.

http://blogs.windows.com/bloggingwindows/2015/04/10/new-windows-10-technical-preview-build-now-available-for-phones/?OCID=WIP_r_Mar_Body_SecondBuild

It supports most Microsoft and Nokia Phones but will not support Nokia Icon. There was almost a year delay even to get Windows Phone 8.1 on Nokia Icon and now this.

List of supported phones:

    Lumia 1020
    Lumia 1320
    Lumia 1520
    Lumia 530
    Lumia 530 Dual Sim
    Lumia 535
    Lumia 620
    Lumia 625
    Lumia 630
    Lumia 630 Dual Sim
    Lumia 635
    Lumia 636
    Lumia 638
    Lumia 720
    Lumia 730
    Lumia 730 Dual SIM
    Lumia 735
    Lumia 810
    Lumia 820
    Lumia 822
    Lumia 830
    Lumia 920
    Lumia 925
    Lumia 928
   NOKIA ICON
    Microsoft Lumia 430
    Microsoft Lumia 435
    Microsoft Lumia 435 Dual SIM
    Microsoft Lumia 435 Dual SIM DTV
    Microsoft Lumia 532
    Microsoft Lumia 532 Dual SIM
    Microsoft Lumia 640 Dual SIM
    Microsoft Lumia 535 Dual SIM

The good news is that there will be a fix (?) although release date is TBD.

Here are the new things in this build:

Project Spartan - The killer rendering engine a great fit for mobile web. It can exist with IE11.
New Calendar and mail apps
New Phone and messaging app - Changing message to voice is not sweat.
New People app
New maps app - Voice guided navigation
App Switcher update

Read more at the link above.