Well it took weeks for results to come back, but they are in. 570 Becquerels of Sr90 per kg of soil are confirmed, along with 4400 becquerels of Sr89/kg of soil detected from samples dug as deep as 5cm into the ground. From NHK:
"Up to 570 becquerels of strontium 90 per kilogram of dry soil were detected in samples from 3 locations. They were taken on April 18, about 500 meters from the Number 1 and 2 reactors at soil depths of up to 5 centimeters. The amount detected is about 130 times higher than a previous high, level that was measured in Fukushima Prefecture before the accident at the nuclear plant.
TEPCO also said it found 4,400 becquerels of radioactive strontium 89 per kilogram of dry soil taken from the same location.
Earlier in March, strontium was detected in soil and plants outside the 30-kilometer zone around the Fukushima plant."
Why should this be surprising? Significant amounts of Sr90 are found in spent nuclear fuel and nuclear waste. Since the reactor explosions in March, many nuclear physicists have been curious were all the strontium had gone, since the first tests showed such small quantities. Now they know. If it managed to get into milk in Hawaii, it certainly would exist in higher quantities in the vicinity of the plant.