Hi Joe,
I'm not thinking its feasible to use that in the newsletter. None of the javscript widgets would work and probably also the css based layouts will also not work in email. Email does not get its style from the skin css and those templates are designed based on css expected to be in the skin.
You really need to use hard coded inline styles for many things in html email. Some but not all embedded css can work, but in general whereas we try to use web standards in the site, email is a different animal with a whole lot of additional issues based on whether using gmail, outlook or whatever email client and getting predictable visual results in all email clients is very tricky business.
Best,
Joe