Vertical tabs are high on my list. I'll try to squeeze them into the next release. However it will be the variant with horizontal text. Let me know if you are actually looking for tabs with vertical text.
Creating a template with Accordion is the way to go. Inheriting from this template will let you change Accordion's selection and add specific content.
Asaf11 Dec 2012
Horizontal text makes more sense to me and it's more usable, so IMO this is a the way to go - waiting for it ;)