Vespalad44 chimes in:

I was flipping through my 'the art of star wars episode 1:tpm' and found some interesting conceptual art not used in episode 1, but in episode 2! Page 82-83 are clearly the flying whales of kamino. Page 116 has a ship with a solar sail. Page 120 has the 'bubble' gun turrets used by the clone army, and page 121 shows R2D2's rockets! Pretty cool stuff!

Update: A few updates from readers. The first from Ken:

I just read Vespalad44's observation that concept art from Episode I was used in Episode II. I remember reading somewhere that the concept artists were given three years of work before TPM compared to one year before AOTC - apparently the first era was intended to establish visual trends for the entire prequel trilogy. Vespalad44 missed a few worthwhile examples of reuse from the Episode I artbook, including Anakin's Jedi costume (the one based on Mad Martigan) on page 202, 33 unused Padme costumes on pages 112-113 and suggestions of the super battle droid on page 18.

Robert adds the following:

The "flying whales" go a lot farther back than TPM. As is the case with many "borrowed" elements of the new Prequel Trilogy design, check out the work of Ralph McQuarrie, specifically, the 1995 book "The Illustrated Star Wars Universe."

The "flying whales" (airwhas) are clearly depicted as part of Bespin (one painting appears before the title page.) The cover illustration to the book itself shows Jawas camped out, with tents, sandcrawlers, etc., as seen in AOTC.

This is just the tip of the iceberg as far as McQuarrie's influence (as well as the work of many artists from the Classic Trilogy.) It would be a shame if this generation's SW fans knowledge only goes back as far as TPM, without recognizing the "early pioneers!" ;)