Registered just to post this comment. A lot of academic tools use this format. This missing feature is blocking me from always using yED and recommending it to peers. (Now we always copy-pasting everything into http://www.webgraphviz.com/)
If you can install Graphviz, you can use the gv2gml command to convert a DOT (gv) format file to the GML format, which yEd is capable of reading. On Mac OS, I used Homebrew to install it (`brew install graphviz`).
You could try dottoxml - http://dl9obn.darc.de/programming/python/dottoxml/