The new product uses percentages to declare font sizes. Percentages are the most safe way to do so, as none of the major browser vendors choke over them as much as ems, or points.
I created a
percentage-based stylesheet a while ago for TrekBBS with relative ease. Everyone uses it as the default. Feel free to use it as a cheat-sheet. (It's a 6.4 style, though, and there are a few hacks on the board...)
The new product uses tables for layout. Non-table based layouts, while superior in a few ways, also are very difficult to style and integrate properly into most website layouts.
The new product will also take the WCAG guidelines into account. We'll be shooting for A-level, with a chance for AA-level.