Friday, June 11, 2010 at 6:03 PM 
Image by Mark Wilson / Getty Images
First Lady Mrs. O delivered the commencement address at Anacostia Senior High School in Washington, D.C. on Friday, wearing a robin egg blue dress, accessorized with a double strand of pearls for the occasion. Lovely!
Update: Mrs. O wears a Michael Kors Surf Stretch Boucle Crepe Sheath dress.
Michael Kors Tuesday, April 27, 2010 at 3:36 PM 
Official White House Photo by Lawrence Jackson
Thank you to Anagrom, who spotted fantastic photos of the president and first lady posing for pictures with members of the U.S. Winter Olympic teams during their White House visit last week. The full album can be seen here.
The orange dress, I believe (and as suggested by others in the comments) is the same Liz Claiborne dress Mrs. O wore for her appearance on Iron Chef America earlier this year. Vice President and Dr. Biden also joined the photo session, with Dr. B dressed in patriotic red, white and blue.
Update: Dr. Biden's dress is Michael Kors Spring 2009, seen on the runway, here. Notably, this is the same collection that produced the black Michael Kors dress Mrs. O wore for her official portrait.
Official White House Photo by Lawrence Jackson
Liz Claiborne, Michael Kors Wednesday, April 7, 2010 at 1:59 PM 
PRNewsFoto/Good Housekeeping
The first lady is on the cover of Good Housekeeping's May 125th anniversary issue, wearing a teal wrap dress, accessorized with a classic strand of pearls. The first lady's Garavelli diamond flower pin - a gift from the president - adds a touch of sparkle and personal sentiment. Lovely!
Update: Mrs. O wears a Michael Kors Marine Stretch Matte Jersey Starlet sheath dress on her cover of Good Housekeeping
Garavelli, Michael Kors Friday, April 2, 2010 at 5:10 PM 
Image by Evan Vucci / AP Photo
The first lady visted the United States Trade Representatives office in Washington, D.C. this afternoon, dressed in a Michael Kors sleeveless doubleface sheath dress -- the color of which was officially described as "melon" -- paired with a white cardigan and snakeskin heels. Lovely!
Michael Kors Wednesday, January 13, 2010 at 6:08 PM 
Image via Jezebel.com
The first lady is featured in this week's issue of People magazine, wearing a Michael Kors Pre-Fall 2010 red rose print stretch cade shift dress. A peek of the dress can also be seen here. Fingers crossed the story and photos will be available online. Has anyone seen it yet?
Update: Though the story is not yet online, Jezebel.com has a good overview here. Thank you Britt, for the tip.
Michael Kors