Deadpool is still the greatest movie of the year. I can confidently say that in April, no other movie will be better from a fun point-of-view. It was so great it set the record for highest-grossing R-rated movie ($757.3 million worldwide.)
The money alone guaranteed a sequel (and probably a part 3.) Fox studios has officially confirmed the news and given it a tentative release date.
From ComicBook.com:
The movie will see the return of director Tim Miller, writers Rhett Reese and Paul Wernick, and of course, star Ryan Reynolds. As has been talked about since, literally, the end credits of Deadpool, Cable will join him for the sequel.
20th Century Fox previously announced that they reserved the dates of October 6, 2017 and January 12, 2018 for untitled Marvel films. Deadpool 2 will likely take one of those slots.