Well back -- chosen by about 20 percent of the participants -- were the users of those networks: human error is the top fret one in five of you listed.
Coming in third was the challenge of holding onto good, qualified IT staff -- interesting, particularly in light of, as Naomi Grossman pointed out in bMighty yesterday, the risks that accompany losing IT staff.
Nothing earth-shattering in this survey, but a good reminder that even as new technologies, approaches and tools come our way (a bit more than 6 percent of the respondents listed access to current tech as their top concern) it's still networks (including wireless) that are IT's top focus.