I mean, Marvel still beats out DC like it always has. Secret Invasion whooped up on Final Crisis (granted Final Crisis was even worse than the banal Secret Invasion IMO) and even a story like Blackest Night that is shaping up to be superb (and DC's best event since Identity Crisis)is losing out to Captain America Rebirth which...so far has been mediocre.
I think WB has helped DC quite a bit. Most people who get pulled into DC comics probably saw one of their cartoons first. There is no denying that DC has always had the advantage in the cartoon battle. The 90s Batman was great. Does it translate into sales? Probably not by much, but I don't see it harming them.
The good thing I see coming out of it is that the comic side of the business isn't being pushed to perform, so we might see books that were too risky before.