I did a bit of research back in the day, and decided to 'side' with HD-DVD. But its a close call, as far as the consumer is concerned. Even though the HD-DVD only stores 30GB, the argument was that you really didn't need the extra 20GB, since there would never be anything to put on it. You could put all the extras you wanted and it would never get full, even in HD format.
Another argument in the case for HD-DVD was that the discs and players were extremely cheap to make. Basically, only slight modifications to existing DVD factories had to be made in order to make HD-DVDs. This would result in the prices dropping much faster after the initial boom. Blu Ray has to make entirely new factories / equipment in order to produce their wares.
With Blu Ray winning, it basically just means that the average consumer won't buy their hi-def movie playing stuff until a few years later down the road, until production costs drop dramatically.