Alongside today's announcement of the next DLC, 2K and Gearbox have also released a new patch for the Windows PC version of Borderlands, enabling access to the first content expansion, previously only available to PS3 and Xbox 360 users.
The 200MB patch can now be downloaded locally
from AusGamers files (note: this patch doesn't actually include the content, it just unlocks the ability to purchase and install it). There's also a PC De-authorization tool
provided for the purpose of managing the secure-rom 5-machine install limit.