Marvel's recent announcement of exclusive deals with Joseph Michael Stracynski (JMS) and Kevin Smith (see 'All Spider-Man, All the Time') could be seen as a response to DC Comics forging similarly exclusive deals with Brian Azzarello, Warren Ellis, and Mike Carey. It's the same old thing as the two industry leaders endeavor to lock up top talent, but there's a major difference between the current bidding war for talent and what took place ten years ago. The beneficiaries of the aforementioned exclusive deals are all writers, while ten years ago in the Image-dominated go-go market of the early 90s, it was the artists who were getting all the fantastic offers and exclusive deals. Strong stories with good narrative flow and character development have never been more highly prized than they are today. Sure there are still plenty of artists (and artist/writers like Frank Miller and Mike Mignola) who can still sell books based on their style alone, but the real superstars of this era are writers such as Alan Moore, Neil Gaiman, Grant Morrison, and a handful of others including the 'exclusive' scribes mentioned above.
Why has the pendulum swung back so far in the writer's direction? In part it's a reaction to the vapidity of stories told by too many comic artists who were long on technique and flash but short on narrative drive and characterization. Of course the drawing (or painting) is always going to be an important factor in the popularity of any comic book, but since no artist has really forged (or synthesized) a daring new style since the rise of Image in the 90s, art style alone is rarely the determining factor in the success of a contemporary comic. The rise of the Internet, where writers like Warren Ellis are able to exert considerable influence, and the increasing importance of sales of graphic novels in bookstores where Alan Moore's Watchmen and Neil Gaiman's Sandman trade paperbacks blazed the trail, also figure in the current ascendancy of the writer. As with any trend there are plenty of exceptions -- and one could easily make a case that artist/writers like Frank Miller (Dark Knight Strikes Again) and Daniel Clowes (Ghost World) are actually the most important creators of the past year -- but there is no denying that now is a very good time to be a writer of successful comic books. 
