Mac sales are on the rebound following the terrible early months of 2009, says Morgan Stanley analyst Kathryn Huberty. While growth has sat in negative territory for a good deal of the year, a fact typically attributed to global recession, May saw shipments climb 25 percent month-over-month, as compared to overall market expansion of only 1 percent. NPD figures have continued to rise in recent weeks, spurred by the announcement of updated MacBooks.