Pokémon Go Hub has confirmed the nest migration has occurred, and certainly a Silph Road post is sure to follow shortly. If you're looking for how to check those ever-ephemeral migratory Pokémon nests, we've got you covered.
Where to check your new nest spawns
As per usual, you can check what Pokémon are showing up where post-migration by using the Silph Road's Global Nest Atlas, which is currently pretty sparse because of the fortnightly shake-up. If you'd like to help fill out the atlas quickly, you can register a Reddit account with the Silph Road subreddit and start logging where you notice certain Pokémon spawning. If you're not so inclined, the Global Nest Atlas should already have some confirmed nests for you if you're itching to start filling out that Pokédex.
Additionally, if you're looking to commiserate about unlucky nest changes, there are a number of city-specific subreddits you can browse as well. You can also post in the general nest migration update thread in the Silph Road subreddit as well.
You've got two weeks before these spawns change up again, so make them count. Good luck and happy hunting.