-2 or more degrees of camber up front is less than ideal for a street setup if your looking for great tire wear. However, you can get away with it to some degree if you run zero toe. Any toe in or out is going to increase the amount of wear. It's still going to wear the insides more, just not as quickly as if you have toe in OR toe out.
What I find funny is how everyone thinks -3 degrees of camber is the magic number for the track. I've found that -3 degrees is too much on my E46 when running a 275 square setup. Other things come into play here like spring rates, tire widths, etc. The best way I know to determine the right amount of camber is to test tire temps. If you're not checking tire temps you simply do not know what the magic number is for your setup and driving style.