They also patched a much smaller number of issues in Leopard, suggesting that many of the fixes given to OS X 10.4 were already included as part of what Leopard had. That's not surprising, considering some of the flaws, like the flash player flaw, have been public knowledge for several months.
Given the dramatic increase in popularity that OS X has brought to the Mac world, it seems likely that with each successive month rolling by that Apple will be more inclined to issue patch releases on a regular schedule. While same may laugh at Microsoft's “monthly patch cycle”, many others have come to expect and rely upon it. Perhaps the same will be true for OS X.