Sander Viegers is a user experience (UX) designer in the Office Design Group who contributed to Excel 2007's development. Sander has guest blogged on the Excel 2007 team blog this interesting post describing the process of creating the new charting experience.

Pencil and Paper Sketches

Thanks to Andy for pointing out the post (btw, check out this post by Andy Edmonds about one of the Live Labs funded research projects on deep clickstream analysis).

Other posts on the Excel 2007 (nee Excel 12) team blog of note: