By Lindsey Unterberger

No, Justin didn't take Scarlett Johansson or Jessica Biel as his date. And John Mayer's new gal pal Jessica Simpson was a no-show too. But just because the most hyped potential couples fizzled doesn't mean other twosomes didn't sizzle at the 49th Annual Grammy Awards. Check out which duos were hot, which were, well, not and who was missing.