What Rys'work does is contribute a way of considering Brontë's
Jane Eyre. It suggests readers ask why Rochester's first wife went mad--that is, it prompts readers who might not think to question Rochester's version of events. Certainly the events are momentous enough that Jane solidly understands the potential for her to become a second madwoman, (and who knows, perhaps she does) even as many readers fall under the sway of Rochester.
I'm not particularly a fan of
Wide Sargasso Sea as I always felt that it could have done better at exploring the Creole woman's plight. Still, it stands as an interesting extrapolation of a world beyond the constricted Victorian moors--Caribbean colonial expansion, race relations, second sons and remittance men. In giving 'voice' to a character who is spectacularly silent in the original text, it of course presents a perspective which may or may not have been outside or beyond that of the original author. That is, it gives us a more contemporary reading of one aspect of the original work.
There's lots being done about Victorian fiction this way. Consider
The French Lieutenant's Woman, or A. J. Byatt or even Johanna Clarke. If this is 'fair'--that contemporary writers look at the silent spots in earlier work, to explore those gaps from our world view--then there's no reason why a writer can't do the same thing to Tolkien. It wouldn't necessarily be from a "politically correct" point of view, but would in fact represent a way one writer critically rewrites a predecessor. This, I think, is a far different kettle of fish than that earlier discussed here.
Frankly, I'm waiting for a post modern deconstruction of
Tom Jones. Fielding already provided one for
Pamela but I think Fielding is ripe for the taking.
