The vertical tabs feature is exactly what it sounds like. Instead of having all tabs appear in a row at the top of the browser, they appear in a vertical stack on the side. This allows you to see a lot more tabs at once than what can fit in a horizontal row.
"Big Cable has had a pretty good run charging people whatever they want and calling it a promotion. We figured it was time to offer something radically different, like one clear price that doesn't slowly morph into something horrifying."