I found the ultimate equation editor: LaTeX Equation Editor. The best part is that I can just copy and paste my LaTeX code for the equations I need from my NIPS paper and BAM! I got a pdf or tiff of the perfectly formatted equation! Piece of cake!
But, I hit a snag. Powerpoint doesn't deal with pdf transparency properly, so it leaves a white border around it....eww. Attempts to set a transparency colour results in an ugly equation. Powerpoint apparently converts the pdf into a bitmap. Fortunately, LaTeX Equation Editor can also export to TIFF, which supports transparent backgrounds. But when you import these into Powerpoint, they look like crap. I found that if you set the export font size to 72, then resize it, it looks great! There are other options like setting the equation colour, etc, but I don't need that. The best thing is that it's damn easy to use, fully supports LaTeX cuz it generates the equations using LaTeX, so no compatibility issues! Even does aligned equations! And, importing them into PowerPoint is a cinch cuz you can just drag and drop them right onto the slide!