What has happened to them? They have ALL dropped one zero for the reward. They could've at least halved it, instead of making them 1/10 of what they were. Frostmaw used to give 3000 norn points for killing him.
The giant bonus is only for the first time you do the dungeon. Afterwards, it's a small reward to make you feel better. There are better ways to get rep, you do dungeons for the loot.
Yeah it's really kind of stupid. Anet really knows how to make things unworthy fast, they should have made it around 30% of the original point reward..but nooo.
The secret lair of the snowmen is also 300 on the first run (but it is a pretty easy and quick dungeon). The <whatever> menagerie was 3000 Vanguard points (at least on the first run, haven't done it again). I ran Menagerie last weekend and Snowmen tonight.