This is the cover to the December free Marvel Previews catalogue that will be revealed later this week. And, as promised, it reveals that Phoenix Resurrection: The Return Of Jean Grey #1 is indeed an actual comic coming in December, it is by Matthew Rosenberg and Leinil Yu and, yes, it is the return of Jean Grey as an adult – and as the Phoenix.
And it is just part one.
You can also see how Marvel is preparing variant covers and Phoenix-replated reprints to promote the series here. There's the pretty damn likelihood that this is the return of an iconic figure for Marvel Legacy – the answer to Marvel's Tom Brevoort tease of "the return of a central piece of the Marvel mythos that readers have been mourning in recent months."
Jean Grey, introduced in X-Men #1 in 1961 as Marvel Girl was the Smurfette of the team, but in the seventies would be transformed into the cosmic entity The Phoenix, commit genocide and then suicide, before revealing that Jean Grey was safely tucked away in a cocoon at the bottom of the sea. The character would then flirt with the Phoenix force and die again at the hands of Xorn. Since then, a time-displaced Jean Grey from the earliest days of the X-Men has time travelled with the rest of the team to the present day and has been stuck here – again, flirting with the Phoenix force. The recent Generations: Jean Grey and the Phoenix saw her young self from the present meet her older Phoenix self in a fabrication of the past created by Kobik the cosmic cube. Which is intended to have consequences for Jean Grey – and it looks like this series might well be it…
Phoenix Resurrection: The Return Of Jean Grey #1 is published on December 27th for $4.99 from Marvel Comics.