Right now, the patch is going through its various certification processes and should be ready in November. In the free update, you'll get:

• Level cap increase of 8 levels
  • That means that all Borderlands players will now be able to achieve a new maximum level of 58.
  • Owners of The Secret Armory of General Knoxx can achieve an increase to a maximum level of 69.
• End game players that have completed play-through #2 will see enemies scale to the new levels up to the new level cap.
  • That means that if you've completed everything, you can play through the game again and again at a challenging level in order to find better and better loot.
• Item drops (with the exception of COM Decks) will also scale with higher level enemies to the new level cap.
  That means that this Title Update features the highest level weapons to date.
• Other fixes, including DLC4 Achievement/Trophy glitches that have affected some users will be corrected to properly award players for obtaining these achievements no matter which order they were completed in.