Pre-season means nothing really. It's a time for the vets to get back into their groove, rookies to get the feel of full-fledged, real deal NBA talent (not just summer league scraps), and guys trying to make the team an honest chance to showcase themselves. The vets aren't going at 100 mph either during these games. They're just trying to get themselves back in order so they can be ready to go for the season.
LAL will be a good team this season, there's no way around it. Whether they win it all or not? Nobody can say for sure, but they have a good shot. Just have to be realistic about things. They will more than likely finish with a top 4 seed, if not a top 3 and they will probably at the very least make the conference finals if I had to make a guess. The playoffs are a funny beast, you can't fully predict who is going to win this round, who is going to win that round.
All I know is, the Lakers will make some noise this year, you can't say they wont, they'll be one of the last few teams standing, even if we are obligated to hate them just because we are Celtics fans.
Of course, this is all barring some catastrophe like DH killing his back, Kobe or Nash having a season ending injury. If they have the bulk of their roster and their main guys intact come playoff time, they will be a serious threat.
This is just my 2 cents and obviously only time will tell to see how everything truly plays out.