Jenny Packham yellow dress

During the Canada tour of 2011 on a stop at Calgary, the Duchess wore this bright yellow Jenny Packham dress.  Its not quite a shirt dress but the bodice is definitely styled like one, with a button front placket, collar, and short sleeves, paired with a flowy A-line silhouette skirt.

Via DM.

Let me just say the dress is fine, but it isn't a very exciting or interesting dress and paired with the nude shoes the outfit itself is a bit boring.  The waistline here has a bit of awkward placing because it is a bit high, making the bodice fit short on Kate's long torso.  I think the combination of the high waistline paired with an above the knee hemline isn't very good on Kate since it makes her dresses look like the fit is too short for her.
But I like the good balance and proportion of Kate strong shoulder with a fuller skirt.  The fuller sleeves do help mask and soften that strong shoulder while the full skirt helps give a feminine shape.  I like when she mixes it up with fuller silhouettes since she does seem to favor the sheaths.
The only downside is that it was not as appropriate for the windy condition and as you can see in the photo she struggled to keep the hem wrangled  Maybe a slip would have helped or maybe dress weights, but for future reference this would be one occasion where her more structured sheath silhouettes would be better suited.

I didn't find a ready made repliKate but I did come across this interesting pattern set for any of you DIY-ers out there.  It features a pattern for a dress almost identical to Kate's.  It has the same button down bodice with collar and sleeves paired with a flowy fuller skirt.  It even appears to have similar dart placing at the bodice.
Its a bit of a coincidence that the yellow dress is featured so prominently in the envelope, so clearly it is meant to be an inspiration of Kate's original.  The other dress in the set is a long sleeved wrap style.

Simplicity brand pattern set # 1880.