I agree that the studios ultimately had to pick a side and that was what put the final nail in the coffin for HDdvd. But after about 6 months into the "race" I personally felt that BluRay was going to be the winner, based on how many studios were hedging their bets with both formats, picking sides and how many manufactures were on each side.
To me, at the time, it was just an obvious choice.

I also knew someone that was a die hard HDdvd supporter at the time that knew nothing of electronics, but was the head electronics buyer for a company - so that helped me confirm the choice to not get behind HDdvd.