The new paladin combat resource holy power just became significantly easier to track and use in this evening's Cataclysm beta patch. Whereas previously it was simply a buff you had to eyeball along with every other other buff up in the top right of your UI, it now has its own UI element directly beneath the character frame. The holy power gauge starts out as an empty, lifeless shell. As you generate holy power, it lights up in thirds (as you would expect) and glows a bright yellow once you've filled it completely.
I still expect that we will see extensive community modding of this bar once Cataclysm goes live, but it won't be nearly as mandatory as it seemed previously. It was extremely difficult to see holy power as a buff, so this increases its ease of use dramatically. If you want to see how it looks first hand, we have a gallery of the gauge in action below or a video embedded above. Go ahead, pick your poison.
Gallery: Cataclysm Beta: Holy Power UI