Thumbelina by Sylvia Long has a release date for next week, but it is already shipping from Amazon and appearing at brick and mortar bookstores.
I haven't seen the book in person, but the previews have been positive. The book is apparently 58 pages long and would thus hopefully contain the full Andersen version of the tale. So this one would be particularly recommended for slightly older picture book readers, not for a three-year-old bedtime's story. Although the three year old would probably enjoy the book over a few readings and enjoy exploring the pictures.
And to see some of the page spreads, visit Scribd to see 9 layouts. Long's version definitely emphasizes the nature worshipping possibilities of the tale and avoids more of the twee tendencies of other versions. Not surprising since her strength is illustrating natural elements, large or small.
And if you enjoy Long's style, you might peruse her completely unrelated book, but highly recommended, An Egg Is Quiet. (And it is currently bargain priced on Amazon, too. Bargain price doesn't imply it's not a great book!) I've also always been partial to her Twinkle Twinkle Little Star. You can also see more about Long herself on her website.
And to see other verions of the tale, see The Thumbelina Book Gallery on SurLaLune.