To be precise (and I do agree with alanw) you need to do all of this:
Assuming you are ALREADY in the Media section...
1) Click Media Manager
2) Click Library
3) Click Music
4) Click Albums
5) Click the Album you like (assuming you see it in the default list, otherwise click click click until you see it)
6) Click Play Now
Phew! That is a ot of clicks! A lot more if you have to double-click LOL
Not sure why, but it appears that the Genre/Artist list item is now nested one folder deeper. I recall in 1.5 one would press Library, then Artist, and that was it.