Updated US sales estimates from the NPD Group hint that Apple sold about 4.9 million Macs worldwide during the December quarter, according to Piper Jaffray analyst Gene Munster. Data is now in for all three months, showing US sales up 12 percent year-over-year. The 4.9 million figure is, however, a lowered forecast on Munster's part -- 300,000 units below a previous target, even if that would still mean global growth of 18 percent.
