Did Paul still want to visit the Corinthians?

Yes, Paul still wanted to visit the Corinthians. According to the context, he desired to come and see them and to stop in there again physically. Until he could arrive, they would have to be satisfied with hearing from him only by way of his letters.

Les explains that Paul still wanted to come and see the Corinthians, desiring to stop in there again physically. But until he got there, they would have to be satisfied with hearing from him only by way of his letters. Earlier, Paul wanted the collection taken before he arrived so they wouldn't be under his influence or give just because he was present. The rest of the chapter is more or less in closing.

How were the Corinthians to hear from Paul until he could visit them again?

Until Paul could visit them again physically, the Corinthians were to be satisfied with hearing from him only by way of his letters. He still wanted to come and see them, but in the meantime his written letters were the means by which they would hear from him.