Keep in mind that you may also have to recode a lot of javascript

I've seen a lot of selectors based on html table tags.
While I feel like this is a good idea, it's benefits may not out weigh the time it takes to do (since there aren't really any benefits except from creating a semantic markup and some stylistic issues).
I just recommend reusing selectors as much as possible, while probably already considered by you, just remember that styling a board that has over 100-200 selectors would take a very long time.
I encourage you to go forward and would help design styles to gather support for this, provided it's not more difficult than current vb