Microsoft, Cisco, Exxon, GE, etc. are all doing this. When you're a bit multi-national company it just makes sense to harbor your income in countries where the tax rate is lower.
I don't fault them for this. They're just waiting for another "tax haven" to bring it all back, and we should probably do that right about now. It'll be a nice short-term boost to revenue.
Long term I'd like to see us drop the corporate tax rate to compete with the rest of the world. That means dropping it to around 15-18%. There are multiple reasons for this.
1) It prevents the desire to off-shore profits. That means more tax revenue.
2) It promotes keeping the income within the company and not handing it out as bonuses to execs. Hence they use the money to further their business which stimulates growth.
3) It lets the "small" guys compete on an even playing field. The small guys cannot offshore their income. The big guys can. Competition is always good.