Search string: Reset all new Kindle Touch's
If you have any initial problems with the Kindle Touch, do a hard reset.
Press and hold the power button for at least 20 seconds, then let it go. If the Kindle does not begin the restart process (boy under tree, progress bar), then press the power button once. It takes about ten seconds for the progress bar to show up, so be patient.
Your Kindle Touch will awake fully functional, and you can delete the corrupted Welcome letter that caused the problem.
So many people have been helped by these instructions that I decided to create a dedicated thread. Amazon won't own this problem, so I will. I included the search string at the top for the Christmas blitz.