Spring 2024, exactly after 7 years from the original Switch launch.
Launch games? Metroid Prime 4 (dual release), Mario Kart 9, followed by a new 3D Super Mario (Odyssey 2?) by the end of the year.

That's my bet :)

I'm gonna say Fall 2024 is most likely. I could see Spring 2025.
I'd say Spring 2024 is a possibility only if sales drop a bunch in 2023, but that doesn't seem too likely with BotW2, possible price cuts, and presumably plenty of other games getting ready for 2023.

2024 feels too soon for a new system but with Switch holidays starting to lose steam I'm guessing they'll want to have the successor out for 2024 holiday. And unless they start doing another round of some of their games on Switch it feels like they'll have plenty of games to get up to holiday 2024 but not beyond, at which point MK9, 3D Mario, Pokemon, etc should be ready with next-gen iterations.

Holiday 2024 is what I think currently unless 2.5 years ends up not being enough time for things to improve enough to prevent the Switch 2 from dealing with major shortage issues.

Until the chip shortages is fixed we will proably wait a long time

I voted on my wishful thinking for a Holiday 2024 (I would be very happy with having the successor earlier on, to be honest), but I have been thinking the shortages will push it to 2025, maybe March as it happened with the current one.

When it's done