Based on the trailer, it seems the series should be good. Matt Ryan embodies the spirit of the character enough to convince me he was the right choice for the role. The show’s creators have brought in an angel, who warns Constantine of coming troubles, and the daughter of a friend who sees dead people. It looks like it will be an edgier Supernatural ( one of my guilty pleasures up there with Pretty Little Liars). Comparing Constantine to Supernatural is not a bad thing if the show can keep a lid on the cheesier elements found in Supernatural.
It appears the show is moving John Constantine from England to the United States. It would be nice, if the series survives past season 1, to see John Constantine back in jolly old England. Taking Constantine out of England is like taking Batman out of Gotham City (which DC seems to do a lot in the comics), it doesn’t feel right. The city John Constantine lives in is just as much of a character in the story as Constantine, Chas (the cab driver), or Papa Midnight.