Sitting at .500 early in the season, while not a good thing, is definitely not a bad thing either. It road going forward is easier the more wins you have by this point, but that's all it's good for. Current records are not useful for gauging the strength of a team. We know this because the Red Sox have only 2 wins (the least,) and are certainly not the worst team in baseball.
The main thing to look at is games back. The Cubs are a skinny 2 games behind the Reds right now and only a half game back in the wild card. Really, we can't even look at anybody's stats and say much about who's going to have a good year. Right now the Cubs are playing ok. It could go either way as the season progresses.
If you do want to make some claims right now, realize that the Cubs are tied with the Giants, defending world champs.