X-bit Labs reports 13" business notebooks are on death row as most manufacturers are now focusing on smaller models:
Laptops in 13" form-factors pose a number of advantages compared to both 12" and 14"/15" notebooks. For example, Lenovo Thinkpad X301 with 1440x900 screen resolution and a DVD drive provided better user experience that the vast majority of 12" and 14" notebooks while being very slim and generally smaller than any 14" machine. However, it came at a too far premium price since models like X301 feature a plethora of first-class capabilities.
Unfortunately, it looks like the end of premium 13" laptops is near. Lenovo has scrapped the X3-series with optical drive. Dell Adamo XPS, which was among the slimmest notebooks on the market, eventually appeared as a proof of engineering and is not currently available widely. Original Dell Adamo that used to cost around $1500 is now available for some $899 that U.S. Dell online store. According to a report, Apple Macbook Air will be another victim of the trend.