I wouldn't wait on that, it's probably still months away (yes, I'm on the Alpha team). Plus, if you think upgrading this skin to 3.8 would be tough, forget about 4.0
It's been on 3.6 for this long, so I'm sure it'll survive another few months.
Converting a 3.6 style to a 3.8 compatible style isn't THAT hard though, the main pitfalls are basiclly the member profile and the parts of vBulletin (like the social groups) that uses a tableless way to style the page that might create some minor issues after an upgrade if the style and css properties in the control panel is heavily customized.
Even for this style, it shouldn't be much more than a few hours of work, even less if people work together and then some testing and done.