Here's a vignette we're dying to see on the ABC broadcast of Sunday's Ford's Theatre Presidential Gala: When Stevie Wonder sat down at the keyboard center stage, President Bush in the front row got very excited. He smiled and started waving at Wonder, who understandably did not respond. After a moment Bush realized his mistake and slowly dropped the errant hand back to his lap. "I know I shouldn't have," a witness told us yesterday, "but I started laughing."