So, no, online course cannot replace in-person teaching.
Sure the gap is narrowing as technology improves communications. Yet it's clear to us that a good teacher conveys more to his or her students in every minute of a one hour in class than any great online course ever could deliver.
And decent distant learning is not cheap. A Times' article, Digital Domain: Online Courses, Still Lacking That Third Dimension, by RANDALL STROSS (which in fact reads like an op-ed) spells out the cost and limitations of the process and hints at its promise.
...Developing that best-in-the-world online course — in which students would learn as much, or more, than in an ordinary classroom or a hybrid online class — requires significant investment. The Open Learning Initiative at Carnegie Mellon University, which has developed about 15 sophisticated online courses, mostly in the sciences, spent $500,000 to $1 million to write software for each. But neither Carnegie Mellon nor other institutions, which are invited to use its online courses, dares to use them without having a human instructor, too...more...And you know what? Because it's in the Times we tend to cut an article some slack, to allow it some credibility, on the assumption that it has been vetted by professionals.
But really, the article starts off, "WHEN colleges and universities finally decide to make full use of the Internet, most professors will lose their jobs."
That is the single stupidest statement I ever read about anything. So dumb, it's not worth rebutting and hard to imagine how it slipped by all those editors.