One reason that relatively new, small vendors can now get access to large companies is that Microsoft, which once dominated many enterprises with the Windows operating system and a full suite of PC applications, has missed many of the new trends of the past few years, the executives said. Rivals such as SalesForce.com have stepped in, changing IT administrators' attitudes, Levie said.

"You're going to mix and match best-of-breed applications instead of just going to one provider for all your solutions," Levie said. Microsoft's foibles have opened up a big opportunity in the mobile arena, as for example the company has only a handful of applications for the entire iPad market, he said.

These upheavals will change the makeup of the enterprise software market for good, in a shift as big as when workers started to demand Internet access at their office PCs in the 1990s, MobileIron's Tinker said.

"I think we're going to look back collectively on 2011 and look at this as the year that mobile IT was born," Tinker said.

Along with this new opportunity will come security challenges, as enterprises shift from assuming internal communications will run over a private network to accepting that most traffic will be on public carrier networks, Tinker said. How to safely divide a single handset between professional and personal uses is another issue, he added. Another challenge will be making mobile software run on multiple, frequently updated operating systems, and work with other mobile applications, Box.net's Levie said.