Judd Apatow's long-awaited follow-up to 'Funny People' finally has a trailer, and it brings all the humor and heart we've come to expect from Apatow and Co. 'This is 40' is a semi-sequel to 'Knocked Up,' reuniting Paul Rudd and Leslie Mann as a married couple coping with the big 4-0.

Where 'Knocked Up' was a coming of age story about dealing with an unplanned pregnancy, 'This is 40' is a coming of middle-age story about dealing with life when you reach that certain age. Rudd and Mann are joined by Iris and Maude Apatow, real life daughters of Apatow and Mann, in this story of reconciling your expectations with reality.

Mann and Rudd reprise their roles as high-strung Debbie and laid-back Pete. Now approaching 40, Debbie is unwilling to admit her age and has to come to terms with the fact that maybe she hasn't accomplished as much with her life as she would have liked to by now.

The film brings together Apatow friends old and new with Melissa McCarthy, Jason Segel, Lena Dunham, Chris O'Dowd, John Lithgow, and... Megan Fox? Yes, Megan Fox.

'This is 40' hits theaters December 21, but you can get excited about it now with this new trailer: