Leaky and Mugglenet both have the cover art details now for both the US and UK (children's and adult's) versions.
http://www.the-leaky-cauldron.org/#article:9653
http://www.mugglenet.com/app/news/show/751
Be warned that if you click on the 2nd link (the one that goes to Mugglenet), they have the images right there so if you only want to see one or something, go via Leaky which has no images on the page I linked.
The US edition will be 784 pages, the UK edition 608. Leaky has also released an episode of Pottercast today to talk about it (which I'm currently downloading).
/tk