Nice work.
Two tips:
1) get the latest version of ICE, the blending is better, details here:
http://hdview.wordpress.com/2011/04/05/microsoft-ice-updatevideo-to-panorama-lens-vignette-improved-blending/
2) When shooting this, use a tripod and shoot on a grid. Then you can use the File:New Structured Panorama ... menu to give hints about the arrangement of the images.