The custom homepage feeds sound interesting. I wonder if users will be able to specify filters to be used. E.g. "Help me discover new DIY creators who have uploaded in the last week and have videos over 20 minutes". Generally I find myself marking videos as "not interested" on the homepage just to change the algorithm, so being able to explicitly say what I want may help.
And if it can help live streams be found and discovered that would be game changing. "Only show me live streams of people playing Tetris, Minesweeper and Chess, sorted by number of live viewers"