They use the same format, but, they interpret the specification in two differents ways. Mister-wong export the list of tags of bookmarks separated by a space and del.icio.us, by a comma. So when you export from Mister-wong to import in del.icio.us, you loose your tags.
So, we just have to replace spaces by commas in TAGS="..." sections. We can do that in 4 commands with vim. Here they are
%s/TAGS/\rTAGS/ %s/">/"\r> g/TAGS=".*"/s/\s/,/ g/TAGS=".*"/j! g/DT/j!
May be it exists shorter way to do it. Do not hesitate to share them.