I discovered a great little utility called itex2MML written by Paul Gartside which converts itex (which is basically Latex) to MathML. Since we can nicely display MathML I used this utility to make a Latex based Equation Editor for AbiWord.
I'm very pleased with the results. This is exactly the way I'd like to enter and edit mathematics in my documents.
Here's is a cute little screenshot of the feature in use. I cooked this up in just about 10 minutes of playing :-)