Interesting, but the simpler way is to use plain html with microformats [1], so this:
@book{kn:gnus,
AUTHOR = "Donald E. Knudson",
TITLE = "1966 World Gnus Almanac",
PUBLISHER = {Permafrost Press},
ADDRESS = {Novosibirsk} }
becomes this: <div class="book" id="kn:gnus">
<div class="author">Donald E. Knudson</div>
<div class="title">1966 World Gnus Almanac</div>
<div class="publisher">Permafrost Press</div>
<div class="address">Novosibirsk</div>
</div>
[1] http://microformats.org/wiki/citation-formats#BibTeXImpressive, this actually 'feels' like an extension for HTML (rather than some custom styles).