So, Phoenix found some ice on Mars. Yay! Here’s JPL’s picture:
Credit: NASA/JPL-Caltech//University of Arizona/Max Planck Institute
So, this is great, but I’m not gasping with shock, or even amazed. This was expected. Also, this is not the first time we’ve found water or ice on Mars. Let me recap an old AstroInfo for you that explains exactly how many times we’ve “discovered” water on Mars.
My post from 2006 . Contains a complete table of the multiplicitous discoveries of water on Mars.
Added 6/2/2008: And now we’re sitting on ice. This is wonderful, this is exactly where Phoenix wanted to be. They want to study ice, because ice is water, and water is necessary for life as we know it. By analyzing the ice, they’ll be able to work on both of their primary objectives: “Study the History of Water in All its Phases“, and “Search for Evidence of Habitable Zone and Asses the Biological Potential of the Ice-Soil Boundary”
Good for them, but remember, it’s not the first time we’ve found water on Mars.
Emily Lakdawalla’s Interpretation: http://www.planetary.org/blog/article/00001485/ 
The Press Release: http://www.jpl.nasa.gov/news/news.cfm?release=release=2008-090b