What's coming now is the 'plug'. It's molten, but very thick. They said early on it might be basically plugged for a half mile or so.
So when all this relatively low temp stuff works it's way out, and fresh lava gets here, we could have steam and ash explosions. The fresher the lava, the more compressed disolved gas it has in it.
So it wont do another 1980, but it could be a pretty big event anyways.
It does make pretty clouds