Diana Ross is very hands-on with planning Ashlee Simpson and Evan Ross' upcoming wedding. E! News has learned that the music legend will actually be performing at her son's nuptials. But Diana won't be the only major icon in the room that night, sources say that Stevie Wonder and Smokey Robinson have also been invited to the wedding. And while the special occasion is bound to be both beautiful and memorable, the 25-year-old dished told E! News that he's more focused on a lifetime with his ladylove.