I see your point. Yes, it is feasible. This can be done similarly to bitmap objects with the use of Ghostscript. When user adds eps or pdf to a drawing, TpX asks him about resolution. Then eps/pdf is converted to bitmap image with Ghostscript for on-screen display (and for SVG export). For pdfLaTeX->pdf way TpX can convert eps to pdf with Ghostscript. For dvi->ps way there is a small problem of converting pdf to eps without losing quality. (Does anybody know how to do this?). Thanks for the suggestion. I've added this to my todo list.