Sending SVGs to browsers in HTML code is easiest way of crushing those browsers ;)
I have FF 2.0.0.16 on Gentoo Linux (P4 1,8GHz mobile, 1GB RAM) and opening this image is very painful:
http://upload.wikimedia.org/wikipedia/commons/7/78/India_roadway_map.svg
How about your's browsers? How about one page with 5 embedded such images? How about 1x1px image with 1M nodes inside?
AJF/WarX