It's been a hard few years for we-control-everything corporate IT departments as well as for the "Microsoft is the answer, what was your question?" approach to corporate computing. It has also been a while since corporate IT departments have had to deal with a new reality that completely changed how they interact with their users.

Once upon a time, IT in most big companies consisted of employees using dumb terminals to interact with, mostly, IBM mainframes. While the IT department enjoyed full control, many users viewed the situation with somewhat less enjoyment. They viewed corporate IT as remote, controlling and unresponsive.

That mode of operation was blown out of the water with the proliferation of personal computers, especially those connected to support local workgroups. The users had rebelled and grabbed control of their own fate. It was a slow explosion and took quite a few years to cause the demise of the dumb terminal business, but the change was impossible to stop.

Still, corporate IT departments figured out a way to subvert the revolution and slowly took over control, then centralized, the workgroup servers and management of the desktops. Strangely enough, not all the users were happy with the return to the old normal. There were a few tweaks, such as the addition of BlackBerrys to the corporate computer constellation, but - the control resided in the IT department - and all was well with the world (at least as far as the IT department and corporate management was concerned).

Then along came the iPhone, something the corporate employees bought for themselves and wanted to use in place of the suddenly crude and clumsy BlackBerry. But IT said the iPhone was not ready to be a corporate player. Then along came the iPad tablet, but corporate IT still resisted - Apple, after all, was not Microsoft, and Apple had a well known distain for bowing to corporate IT managers.

As with the prior revolutionary move to personal computers, the users are revolting and are not willing to take "no" for an answer. The new, snazzy, user-friendly and powerful portable devices, led by products from, but not exclusively from, Apple coupled with the financial constraints inherent in the modern corporate world, have forced more and more companies to let employees bring their own devices (BYOD) to work. It should not take much analysis to decide that letting employees spend their own money on tools they can use for their day jobs is a good deal for the company. But that good deal comes with significant issues.

The most important involve user support and security. Just how much will a company have to spend supporting employees using their own devices? How are company secrets downloaded to employee devices going to be protected? How can the corporate network be protected against a corrupted employee-owned device?

Seems to me that the first issue is way overblown. Remember that there are dozens of YouTube videos of 3-year-old kids running i* devices just fine - most employees should be able to do most things on their own just fine as well. The security issue is a real one and one that corporate IT will have to work thorough, but it is unclear if the risk is that much different than with corporate-owned portable devices.

Apple, with the announcement of the new iPad Wednesday has upped the ante. Few remaining corporate IT departments will be able to resist the tide - and it is far from clear if there is a way to recover the old normal.

Want to read more about Apple's new iPad? The latest issue of iPad & iPhone User, available right now on Newsstand, has hands-on testing of the new features, pictures, availability info and in-depth Q&As to help you decide which model is right for you.