It should be Sugarlabs policy to make the teacher's job easier - teachers who actually benefit from Sugar become Sugar and XO advocates.
A simple fact: Teachers decide when the XO will be used.
Sugar was meant primarily for kids independent learning. School class time has to do with some National Official Program Curriculum.
Performance, salary, and chances for promotion of teachers depend on if and how they achieve the Official Program.
Given any education tool, if it makes the teacher's job easier, it will be adopted enthusiastically. If it requires extra effort, it will be used but seldom. That is human nature.
1) make Sugar relevant - without abandoning the Constructi***st origins of Sugar, align Sugar with the Official Program of Education of Perú and Uruguay - with between 50% and 70% of the total user base of Sugar, this would be a good start. The Textbooks initiative, for example, should be high priority with that goal in mind.
2) evaluate, evaluate, evaluate, not just when or where Sugar works, but, more importantly, where and when it fails. And why. To reinforce, re-orient, redirect efforts.
3) make Sugarlabs relevant - integrate more teachers (and students) to the Community, as we seem to be losing ground - only 6 new members of Sugarlabs, for 2012!