I've been following this for a bit and have managed to get, well, not very far.
But Dan Abnett and Andy Lanning, comic book creators who worked for Marvel UK togethr before moving to Marvel US and DC with titles such as Resurrection Man, Force Works, Batman and Superman, Legion Lost and Legion Of Superheroes, before beginning what would be seen as their joint masterpiece, reviving the "cosmic titles" at Marvel, from something that no one cared about, to something that quite a few people really rather liked, to the extent that Guardians Of The Galaxy is now to be Marvel Studios' next blockbuster movie. That's basically down to them.
Known collectively as "D'n'A", they are no longer working as a writing partnership. Dan Abnett tweeted last month,
@MikeFitz538 I'd love to write a cosmic Avengers book solo, (I no longer work with Lanning) More cosmic stuff from me TBA soon!
— Dan Abnett + Nik (@VincentAbnett) January 6, 2014
I talked to a number of British creators who, while no one had details to share, did confirm that the two were not working together due to falling out badly. Neither commented on the issue when approached by Bleeding Cool, though Lanning did correct a couple of errors in his biography above.
Andy Lanning recently contributed to the Revolutionary War revival of Marvel UK titles, but not his ex=Marvel UK partner. Marvel have new Guardians Of The Galaxy work by their pair lined up for April, but it is likely to a) change or b) be old work finally being published.
It wouldn't be the first time such iconic working partnerships have split never to reform in a similar fashion. Alan Moore and Alan Davis, Grant Morrison and Mark Millar, John Lennon and Paul McCartney… there must be some Americans who have done the same thing too.