- VM support was added to lay the groundwork to support pro-level apps like Final Cut Pro on iPads. My guess is they won't release them this year, but early next year once iOS 16 has been in full release for a few months. I don't think Pro apps were possible before this due to iOS's RAM limits, but VM support changes that.
- Developer mode will make it possible for people to install apps from non-App Store sources. It's buried specifically because Apple wants to make it hard to find, so most users won't come across it. It's also labelled "Developer Mode" vs. macOS's "Allow apps downloaded from App store and unidentified developers" to make it seems like something specifically for developers.