While Windows Phone 8 features Office hub where you can manage you documents and presentations, you cannot create a new PowerPoint presentation from the hub. You have to create it elsewhere and then save it to SkyDrive and then open it from the hub. PIX2PPT is a new app for Window Phone which allows you to create a PowerPoint Slideshow from your pictures hub.
The app is pretty easy to use, simply open the app and it asks you to select the pictures from the picture hub. You can select any number of pictures and then create a new slideshow.
Before you save the PowerPoint, you can add the file name, slide name, orientation of the slide and also the slide auto advance time. When you save the file you have the option to save it to local folder (Office Mobile) or to SkyDrive. Even if you share it to SkyDrive, you can access them from Office hub.
You can also share the link through email with QR code. The app is priced at $1.99, but there is a trial version which allows you to add up to 5 pictures in the slideshow.