There's also this, an article discussing some publishers' attempts to re-brand classics for the young adult audience. Why not? The stories are engaging if the reader is receptive to them. (Any veteran teacher knows this.) And despite the adage warning us not to judge books by their covers, we can't help ourselves. It only make sense to be sure the cover best reflects the novel and appeals to its target audience.
Take, for example, the redesigned cover of Jane Eyre for young adults. It portrays the heroine as whimsical, strong, edgy:
And compare that cover with the Barnes and Noble edition:
The sober countenance hardly reflects Jane's character, and the cover doesn't intimate the delight a reader will find in the pages that follow. The cover art outdated, but the novel is not.
The canon endures because the texts are universal. The accessibility of classics—as free editions and as appealing texts to young adults—will, I hope, warm another generation to the great works of literature.