Lots of people on the Internets are writing their remembrances. I particularly enjoyed this comment from Emma Bull, author and blogger at Tor.com:
"[Diana] was passionate about what children want and deserve from their literature. Adults would approach her at signings, wanting to know why she wrote such difficult books. In one case, when a woman protested, the woman’s young son spoke up and assured Diana, “Don’t worry. I understood it.” She believed in the flexiblility of her readers’ minds, their willingness to puzzle things out, and to wait for clues to anything they couldn’t yet puzzle."
I didn't discover her work until I was an adult, but I have loved what I have read, and I look forward to the pleasure of reading more. Thank you, Diana, for your beautiful legacy!