I had no problem with Stan not having a cameo. He had nothing to do with the creation of Wolverine.
I thought this was great! It felt like a real movie. Wolverine does not really fit the standard definition of a superhero. So making it a stock superhero movie, which Origins was, would have been a mistake. Instead it was straight action/mystery film suited to this character.
I was happy to see the Teaser for Days of Future past was not at the end of the credits. A few people had gotten up to leave when the credits started to roll but stopped to watch this.