Any news whether the official Mango release will allow sideloading of apps? I mean ability to deploy apps without going through the MarketPlace? I would like to see the ability to deploy my own apps on my own device without using third party services and paying extra fees. I don't plan to publish apps publicly. (I tried ChevronWP7 and it couldn't work as intended. Probably obsoleted by MS.)
Yes it will. According to the TechDay event, there will be two channels for side-loading apps. One channel is for Beta apps - specifically for side-loading apps at the Beta stage of development, and the other channel is for private apps which are ready for release.
So the WP7 app marketplace will have 3 channels when Mango is released: