Some sources say yes, some say no. Keanu has NOT flat out said no, he just said he doesn't see it happening. The producer of the first movie said yes to a interview in 2006. Keanu made his statement in 2008. But I think with how bad "The Day The Earth Stood Still" remake was, he should probably be scrambling for the work.
UPDATE (entry 12-30-2020) B. Roxy Rogers, journalist
In 2019 Keanu Reeves *confirmed* that he was interested and willing to play Constantine again. That may have been the driving factor in this project moving into more active development. Also, as mentioned elsewhere, actor Peter Stormare confirmed in November, 2020, that this project was "active." Currently, Lauren Schuler Donner (producer) and JJ Abrams (Directing) are understood to be attached. However, Abrams attachment is recent and as we know, this could change by the day, hour, or minute, so stay tuned.
