If Apple's tablet is so great for business, what's holding up the big deployments?

    Medtronic bought 4,500 iPads for its sales and marketing teams. Boston Scientific bought 2,000. SAP bought 1,000.

    Okay. But where are the rest of the four- and five-figure deployments?

    According to Apple (AAPL) CEO Tim Cook, 65% of Fortune 500 companies are either testing or deploying iPads. But from the reports we've seen so far -- including the seven businesses profiled on Apple's website -- there's a lot more testing than deploying going on.

    In this regard, the results of a survey published Tuesday by Citrix (CTXS), a Florida-based networking company, are instructive. Of the nearly 5,000 Citrix customers polled, 46% said they use an iPad every day (18% for so-called "mission critical" activities) and 62% said they planned to buy one.

    But when asked whether their company was going to purchase iPads, 57% answered no.

    Some of the reasons given include:

    • Concern over security: 63.4%

    • The iPad doesn't meet compliance requirements: 19.8%

    • It's a nonstandard device: 36.6%

    • It's an entertainment device: 19.7%

    • It can't run Windows: 13.1%

    • It doesn't support corporate applications: 24.1%

    • Support for BlackBerry only 14.2%

    Citrix, which makes an app to connect iPad users to its XenDesktop and XenApp platforms, has started Dilbert-themed "iPad at Work" movement. As of Thursday morning, it had attracted 1,898 supporters who say they want to run "all their existing Windows business apps, desktops and data on their iPad."

    Judging from the nearly 1,898 headshots posted on the website, its a pretty broad cross section of computer users.