>I heard Vincent has an upcoming InsetPreview feature which I don't exactly >know how would relate to this, perhaps both things may be worth to exist. >
Well, everything inside this Inset will get previewed. So if you put your equation into an ert into this inset it will generate a preview of the equation. This would only be necessary in cases which the math editor does not handle. A common problem is math insets that need a parameter e.g., xymatrix. Vincent