Two large, open-access* corpora have recently been released.
Go here to learn about and get access to the Spoken BNC2014, and go here to learn about and get access to the EF-Cambridge Open Language Database (EFCAMDAT). EFCAMDAT is a learner corpus featuring essays from adult learners of English around the world, and this is its second, bigger release. Spoken BNC2014 is brand new (to the public), and, as you may very well be aware, is being described as “the largest ever public collection of transcribed British conversations“.
I don’t have anything too special to say. These both look like terrific resources. I think all who are interested should check them out.