Sienna Miller and Jude Law returned to Heathrow together last night. The couple are back in England after celebrating New Year's together, though they were also marking other big days — Sienna turned 29 on Dec. 28 and Jude had his 38th the following day! The couple also had a getaway to mark the events last year, when they took a bikini- and shirtless-filled trip to Barbados. Jude is rumored to have gone all out this time around, though, having apparently given her a $200,000 diamond sapphire ring hidden in a new piano. The instrument could find a central position in their just-purchased North London home, where Sienna and Jude may start living as husband and wife if one of our 2011 predictions proves true.