One of the new features in PowerPoint 2010 are tools on the Ribbon that appear on demand, as you work. These tools will automatically appear as you work in your presentation. They will be relevant to what you are doing at the time.
For example, if you are working with a shape in your presentation, the Format tab will appear, with the Drawing Tools.
Another example would be if you add a table to your presentation. When you click in the table, you will see that the Ribbon now shows the Design and Layout tabs, along with Table Tools.
When you click away from the shape or table, the on-demand tools will disappear, and the standard tabs will remain.