Being that I'm a geology student currently in a volcanology class, the possibilty of a "large" eruption are about 50/50 because predicting whether a volcano is going to blow is ulimately decided by the volcano itself. And since good info seems to be circulating, if/when the volcano begins to display textbook signs signifying a large explosion, word should get out soon enough. Some volcanoes have cycles of eruptions, and I'm not sure about all of Mt. Saint Helens history going back in time further than the 1980 eruption.
The most dangerous thing about the 1980 eruption was the massive mudslide and PDC surges that issued forth from the volcano. So when the authorities establish safety zones, I hope that people will abide by them.
Mt. Vesuvius is one volcano that disturbs me since the area around it is heavily populated. If it chose to erupt...it would be a very bad thing. Not to mention the fun brewing in Yellowstone Park