A majority of the most popular writers and artists working in comics today have plied their trade for both Marvel and DC Comics.
Bendis later retweeted the announcement, confirming it is real and not some nefarious plot by the Anti-Monitor. Ultimate Spider-Man was such a success that it launched an entire imprint at Marvel. It's then that Marvel Comics hired Bendis to help helm their forthcoming reboot they would entitle Ultimate Spider-Man. I am bursting with ideas and inspiriations.
Brian Michael Bendis has always been among the chief writers at Marvel Comics having created some of the most popular 21st century characters, including Jessica Jones, Miles Morales the Ultimate Spider-Man, and Riri Williams, aka Ironheart.
From the major changes to the fabric of the Marvel universe to the small character decisions that take them in new directions for years to come, you can bet Bendis has had a say in most of it for this entire century.
Interestingly enough, Bendis leaving Marvel follows their "big" Marvel Legacy initiative, and Bendis was also a part of Ike Perlmutter's Marvel Comics Creative Committee, so I wonder what has become of that?
Outside of his work on Ultimate Spider-Man, Bendis is behind an innumerable amount of iconic comics for Marvel. A Marvel spokesperson thanked Bendis for his tenure with the company and wished him luck with his future projects. In his time at the company, he's had lengthy stints on Avengers, New Avengers, Daredevil, All-New X-Men, Guardians of the Galaxy and more, along with the event series House of M, Secret Invasion and Civil War II.
Neither DC nor Bendis have announced what titles he will be working on for the home of Superman, or when we can expect to see his first works.