Sang Kim, a partner in the international tax practice at DLA Piper, also said he doubts that the legislation will impact outsourcing. "The argument is that it should stem the flow of jobs leaving the U.S. but the reality is I don't think the jobs are moving outside the U.S because of tax policy," Kim said.

If anything, the tax code changes could accelerate the flow of jobs overseas to offset the larger tax bite, he said.

Kim said there could be unforeseen consequences to the tax changes. A foreign country could, for instance, could offer subsidies to U.S. firms to create jobs as a way of mitigating any tax impact, he said.

The Hackett Group, whose clients include many multinational firms, reviewed data collected from 200 companies to find that at companies with revenues of at least $5 billion, as many as one quarter of IT jobs will be moved offshore by 2010.