These new icons looks almost identical to the ones in Vista, but the most important change is the new bar under the icon that gives you a bar graph of the current drive space.
Download DrvIcon and install it on your Hard drive.
The new icons will look similar to these:
When your drive is running low on space the graph will turn red to indicate that you should probably stop putting information on it.
When you have enough free space on the drive the bar color will be light blue.