I have a somewhat different take on the issue of the diversity (or lack thereof) of the current Supreme Court, which Richard tackled below.
He is quite right that there is not enough representation on the Supreme Court of lawyers with experience in private law. If a national medical board existed (which I hope it will not, but give Obamacare time) to resolve disputes in the medical profession, we would not want it populated only by surgeons or psychiatrists.
But I submit that Richard's issue is more a symptom of the disease, rather than the disease itself. My preference is that the Court have little to do, if possible, with business issues. I worry that the more the Court involves itself in the core meaning of property, contracts, corporations, and so on, the worse the law will become. Far better, in my view, for the law on these matters to be made by the states (as originally understood by the Constitution's Framers), where they are subject to competition for businesses and population. It is a sign of the impetuous vortex for power that is our current Supreme Court that we worry what it thinks about private law and business issues.
Finally, I don't worry about the diversity of background issue as much as whether the Justices have a strong character that is resistant to criticism from media and academic elites. The judge for whom I clerked, Larry Silberman of the D.C. Circuit, once gave a speech on the "Greenhouse Effect," which referred to the pressures -- from the New York Times and the media on the one hand, to the academics and political players in D.C. on the other -- that push Justices to become more liberal over time. Decide a case in a liberal direction, and the Times will say you have "grown" in office and are "exercising statesmanship" (See, e.g., Justices John Paul Stevens, Harry Blackmun, Sandra Day O'Connor, and now Anthony Kennedy, who were all appointed by Republican Presidents but became more liberal once on the Court). How many Justices in the last 60 years became more conservative instead?