Dwarves are a hardy race. They tend to dwell underground in systems they have built. They are stocky and physically strong, making them fine warriors and fighters. They typically do not venture down magical paths, but do have a strong poison resistance... Perhaps it's all the alcohol.
Physically hardy and resistant to poison makes them an excellent defensive race, and their deceptive strength makes them offensively excellent as well.
Perhaps their biggest failing is their stubbornness, not that they'd ever admit it. Secondary to that, they're usually not very good at magic.