We usually do the I-131 about six weeks after surgery. Some center wait 3 months. Certainly should stay on thyroid hormone pills during this time and there is not likely a significant risk in delay until 12/2010 but not sure why the wait (unless school related - which is reasonable). In meantime, would keep TSH 0.1-0.3 range and discuss with your doctors the stage of the cancer and whether there is a likely benefit with I-131.
The staging is important, but there is some evidence that younger patients (esp <16) are at higher risk for more aggressive cancer and some would argue more in favor of RAI, but the key is careful review of the pathology to make sure it is needed.