U.S. senators have accused Apple, the world’s most valuable company, of also being the world’s biggest tax avoider, as congressional investigators yesterday laid out how the technology giant has jumped through tax loophole after loophole in order to save some $44 billion of otherwise taxable income. Today they’ll follow up by grilling Apple CEO Tim Cook on Capitol Hill. Aside from the fact that Apple clearly has amazing tax lawyers, what does all this mean? Here are the four key things you need to know: 1. Corporate tax reform will be the big issue in Washington now that the deficit is off the front burner. As I wrote in back in January, American firms have some $2 trillion in cash on their balance sheets stashed abroad, in large part because they don’t want to bring that money home and pay America’s 35% corporate tax rate. (Ireland, where Apple apparently stashed much of its cash, has a 12.5% rate — though it appears Apple was able to negotiate an even lower one than that.) With unemployment still high, and wages still flat, the government wants companies to bring that cash back to the U.S. and put it work creating jobs at home – and the investigation into Apple’s finances is clearly a warning shot to other major U.S. multinationals. Tax reform is coming, not just in the U.S., but also in other major developed countries (more about that below). (MORE: Senate Panel Says Apple Uses Firms Outside the U.S. to Avoid Taxes) 2. Cash rich tech firms are replacing bankers as the new corporate bad guys. A year ago, I wrote a column called Learning To Hate Big Tech, which led with the investigation into Apple’s tax avoidance, but also laid out other Big Tech v. Government battles, like the push to get Amazon to pay local sales tax (which the government won) and the FTC’s anti-trust investigations into Google. The bottom line is that when you have a lot of cash and can move much of it abroad easily, as the biggest tech companies