To Mike's point, the technology is there. There is a major investment requirement to electrify a piece of track. There are also the complexities that go with trying to operate some trains electrified and some trains diesel-powered. You can't just turn the switch one day and suddenly you're electrified.
The other item that would be a concern from the industry's perspective is that we're not on an island; we're not isolated. We have to interchange with the American railroads and everyone else, so there are also the interchange issues we'd have to work our way through.
But I think the major stumbling block would be the huge cost to electrify our rail infrastructure.