I'm sure we'll continue to see casting rumors to pop up until it was official, but the NY Post previously covered the casting rumors of Javier Bardem and Viggo Mortensen, which were confirmed by Ron Howard as correct, so we're assuming this is correct as well.
The NY Post is reporting that Christian Bale is now the top choice for Roland Deschain in The Dark Tower movie and TV series Ron Howard is working on for Universal. Especially with Bale's recent Oscar Nomination and possible win in the near future, he'd definitely be a name that would allow The Dark Tower to be of interest to audiences who were not familiar with the book series.
The movie has not received the green light from Universal as of yet, so whether or not the project even sees the light of day is anyone's guess. It will take the right mix of material and casting to move everything forward and we'll keep reporting updates as we receive them.