The men's costuming is done well too. I especially love Mark Strong's clothes (see the 1st picture).
Another great example of fabulous costuming for men & women. The following images of authentic clothing from the 1830s & 1840s all come from the Victoria & Albert collection, which is rather appropriate, don't you think?
A close-up of the bodice & skirt from the 1840s. Compare with the above picture of Emily Blunt sitting down in the wedding dress. This waistline is *very* 1840s.
A red stripey dress from the 1840s.
A fellows garb, just to give you an idea.
I'll end with this. It's a beautiful example of a dress from this period, and illustrates perfectly how wild & interesting some of their fabrics were, which is one of the many things which makes the costuming in 'Young Victoria' so lovely - they capture that element perfectly.