A Search Engine Roundtable Forums thread spotlights a feature that Google seems to be testing on select advertisers. The feature appears to be a detailed budget report or analysis, on the edit campaign section, under the budget settings section.
For some AdWords advertisers the section has a "New: Come back in 15 days to get a more detailed budget recommendation based on your campaign performance." There is a link to an FAQ section that reads:
Detailed budget analysis: When possible, we will analyse and display the percentage increase in clicks that you would be eligible to receive with an increased budget. We make this detailed analysis based on your campaign performance data over time, so it is only available when you have not altered your campaign within the last two weeks.
Basic recommendation: In many cases, we will supply a budget recommendation based on historical data for the same or similar keywords as yours. The basic recommendation considers variations in language and location, but it does not consider traffic you might receive from the content network.
Kevin Gibbons has a screen capture of the budget settings page.
Forum discussion at Search Engine Roundtable Forums.