Select the video you want to share with the world. Once you select the share option, you can send the video straight to YouTube or use the Nokia Video Trimmer app to capture and trim the video to include all of the action you want, before uploading it to YouTube.You can do this via either 3G or Wi-Fi, but the video will not upload in the background which means that you must make sure that you are not going to use your phone for anything but sharing your video with YouTube until that mission is complete.
Originally, when we told you about this app, it wasn't working except on those models that already launched with the GDR2/Amber update, like the Nokia Lumia 1020, Nokia Lumia 925 and the AT&T version of the Nokia Lumia 520. Now, any Nokia Lumia model with Windows Phone 8 can upload a video to YouTube, a quite useful app to say the least. It's free and can be found at the Windows Phone Store.
source: NokiaVideoUpload via wpworld.pl (translated), WMPoweruser