There are a number of questionnaires and other reports that could be used to gather data from projects and deployments. Brian Jordan has suggested setting up online forms to gather and distribute lots of data and converting it into spreadsheets and simple graphs.
For a list of research and assessment studies, see OLPC research.
How they are growing / who they are working with; hardware, teacher, and community metrics. Graph of # laptops over time for each deployment (one deployment or country or laptop language per line)
How they are progressing / working with others; what they have and need
How they are being used / hacked / updated; todo lists and future milestones
How are they getting along / who are they working with / what is easy and hard for contribution