The Sony Store US website is now selling the Xperia Z. However, before you get too excited, only the HSPA+ version (C6602) is on sale. The North American LTE SKU (C6606) is notably absent most probably as T-Mobile will be carrying it exclusively. All three colours are available (black, purple and white) and will set you back $629.99. However, it is worth noting that Amazon and Newegg both have it in stock for $599.99.
In addition, Sony has dropped the price of the Xperia ZL (C6506), which supports North American LTE bands, from $759.99 to $629.99. Only the Red version is shipping right now, with both the black and white variants due later this month. Despite the price cut, Newegg is still cheaper at $609.99 and has all three colours in stock.