Using XHTML, the math content should be directly includeable:
<body>
<p>Bla bla bla</p>
<m:math xmlns:m="http://www.w3.org/1998/Math/MathML">
<m:mrow>...<m:mrow>
</m:math>
</body>
- Works in W3C's Amaya browser
- (Looks like) IE 6 will include it, bound to the IBM plugin!