Comment 115 for bug 395749

The low-level functionality seems to be restored, but hasn't been enabled by default for Firefox. I don't think this issue is resolved until it's again enabled by default. This isn't esoteric behavior that only a few people want; this is basic user feedback, at least on Windows.

You can enable it via "ui.use_activity_cursor" in about:config. I don't know if there are still issues preventing it from being used by default; it seems to be working for me, for what it's worth.