We all thought Aerolite Basic will be the default theme in Windows 8, but it is not so. Winunleaked has posted a screenshot showing Aerolite Glass theme. One interesting thing to note is that the Aerolite Glass is not listed in themes menu, instead its been kept as a easter egg in Windows 8. Ofcourse, Microsoft may change any of these things in the final version of Windows 8. Check source for details on how to enable this theme in your developer preview of Windows 8.