Mexico's Valle de Guadalupe is reminiscent of Napa or Sonoma some 40 years ago. This sparsely populated region is ideal for winegrowing, with clean air, open space, diverse soils and a tranquil climate. Hundreds of acres of vineyards are planted each year as millions of dollars are spent on stylish new wineries and boxy warehouse cellars. This is a small wine boom in the making that may dramatically change the region, likely within a decade, if current trends continue. As more discover Guadalupe's charms, the romance of wine in this fertile, affordable high desert land will be increasingly tempting. Wine Spectator's James Laube explains.