Thanks for writing in. It's great to hear you want to learn more about Wii U! I know this wasn't the answer you were hoping for, but we do not have information letting us know which titles will be available for download at launch. However, I can confirm that a majority of Nintendo-published Wii U titles will launch both as a packaged game at retail stores and as a digital download in the Nintendo eShop. - Nintendo customer service rep
Why do I have a feeling that we won't find out what eShop games will be available until the day before...or the day of?! Thanks to Moron9000 for the heads up.