I wanted to really consider this before I weighed in with an opinion, but I think it's time to join the debate.
I loved Michelle's yellow outfit for the inauguration ceremony, I thought she glowed. That shade of mustard is a great colour on her, I really liked the sparkle at the neckline and also the use of texture and layering. A touch more tailoring wouldn't have hurt, but overall I thought it was a winner.
Now I personally would not have chosen the cream ballgown myself, because it had a hint of wedding dress to my eye, but she looked absolutely radiant and you cannot argue with that. As Erin at a Dress A Day has taught me, it's important to wear clothes that make you happy and clearly that dress made Michelle happy. Well either that or her husband having just been inaugurated as the 44th President. W00T! (Also Erin has written about Michelle's outfits too, and she has pictures of them too! She's so organised!)
Doc C and I were talking about it afterwards, and I think it's safe to say that Michelle is the most stylish First Lady since Jackie Kennedy. This may not be the most important element of the Obama administration, but it is still really quite exciting, you know, if you're shallow.