January kicked off 2013 with plenty of celebrity excitement! From the 57th presidential inauguration to the start of award season, there was plenty to keep stars busy. Kate Middleton unveiled her royal portrait, Jennifer Aniston shared a bikini-clad getaway with fiancé Justin Theroux, and Kim Kardashian and Jessica Simpson both announced they are expecting. Plus, Olivia Wilde and Jason Sudeikis let fans in on their engagement news. That's not all that happened this month — click through to see the best pictures and the biggest news of January.