As a sole proprietor, there is absolutely no benefit to incorporation (or running as an LLC). It is pointless overhead. There is no tax advantage (at least not for modest levels of income) and there is no liability advantage. This stems from the fact that you can always be held personally liable for anything you do whether acting as yourself or as the officer of a company. As the company's only officer, you can be held personally liable for anything your company does. The corporate veil is easily pierced in a one person business.

There may be some value of running as an LLC or corporation rather than as a partnership as this protects you personally from the stupidity of your partner. Perhaps, I am over-cautious, however, as I would never even consider going into business with someone where I thought there was any chance of him screwing me over intentionally or by accident.

Finally, if you start having employees, incorporating might be worthwhile to protect you from the stupid actions of your employees.