Here since apparently it's too much work for Hirukaen to just post the information here. I'll do it. This is from the Discord.

"Hi!
We’ve gotten quite a few questions about the Xbox port since the announcement yesterday, hopefully I can answer some of them here:
- Valheim will come to Microsoft Store / PC Game Pass this fall, and to Xbox Game Pass in spring 2023.
- This is not taking time from the development of the Mistlands, as external teams are doing the porting for us.
- There will be full crossplay, meaning you can play on Steam with friends who are using Xbox, or any other combination.
- You will NOT need to create a Microsoft account in order to access the crossplay; if you already play on Steam you can continue doing so just as usual.
- The Xbox version of the game will be as similar to the Steam version as possible. There will not be any split-screen or couch co-op.
- You can join a dedicated server from an Xbox, but you will have to set it up from a PC. Hosting a world without making a dedicated server will still be easy on Xbox, and you can join a game regardless of what platform it is hosted on.
- If you’re using a Microsoft account, your progress will be synced between your PC and Xbox. It’s currently a bit unclear whether or not there will also be an automated sync between Steam and Xbox. We will give you more information about this as we get closer to the Xbox launch.
- There are still no plans for any official mod support."