The patch will likely effect both offline and online players, so you will want to update the software for sure. Yamauchi also confirmed that they have a lot of things in the works for Gran Turismo 6 that will be released over the next 12 months after the game is released.
Apparently the developers are overflowing with stuff that the want to do, so that means that fans should expect a lot of cool stuff in the months ahead.
Read more here.