Marvel SVP of Sales & Marketing David Gabriel teased the upcoming death of a character in March 2015 in a recent interview with Comicbook.com, and all signs point to Deadpool.
 
While fielding a question about the wrap-up of the Death of Wolverine storyline (see "Marvel Provides First Look at 'Death of Wolverine' #3"), Gabriel added "Oh and speaking of death, we were just talking about the upcoming death of a character in March in issue #250 of a character with the word Dead in his name.  Go figure."
 
Comicbook.com’s Jamie Lovett immediately did the math and noted in another article: "If you add up all of the issues of Deadpool’s core series, including the four-issue Deadpool miniseries, The Circle Chase miniseries, and the issues of Cable & Deadpool and Deadpool: Merc With A Mouth, that makes November’s Deadpool #37, the latest issue to be solicited, the 245th issue of a Deadpool series.  That means Deadpool #42 will be the 250th issue of a Deadpool series, and that issue should arrive in March 2015."
 
With the recent scheduling announcement of the Deadpool movie for February 2016 (see "'Deadpool' Movie Gets a Date"), that gives Marvel about a year to plan a glorious return for Wade so he can attend his own movie premiere. 
 
Of course, it may not be Deadpool that kicks the bucket.  Given the great lengths the Merc has gone to in an effort to off himself in the Deadpool Killogy, it may not be Wade himself who dies in that issue.  After all, Wade just got married (see "Deadpool Wedding"), and series writer Gerry Duggan even teased in that announcement, "As for how long she’ll be around, I’m not 100% sure, because when you get close to Deadpool, that’s maybe when I start to think about adding you in my deadpool."