A case when this will still break bookmarking:

- user with JS enabled opens the website and navigates to some inner page

- user with JS copies the url for the inner page (e.g. http://example.org/#foo/bar)

- user with JS sends this url to a friend

- a friend with JS disabled opens the url and does not get the inner page.

Also -- what if a search engine "bookmarks" the page and a user with JS opens it? Do you:

a) redirect him from example.org/foo/bar to exmple.org/#foo/bar or...

b) do you leave the url untouched and wait until the user bookmarks another page as example.org/foo/bar#foo/baz ?

a) -- you waste processing power on visitors from search engines.

b) -- you waste processing power on the next opening of the bookmark. Also this looks like a bug waiting to happen.

Disclosure: I browse with JS turned off (Firefox NoScript extension) and websites that rely on JavaScript when a static page would do annoy me.