If you haven't played since Stress Test, you're going to want to download the last 2 patches soon. I had roughly 1GB worth of patches to download since Stress Test when I started playing again.
If you want to download it early, you might want to try where I got my old Stress Test version from. I don't know where to download the current version, but this would get ya started:
This is a 2+ Gigabyte file, then you'll have to turn around and likely download ~1 gig more in Patches (not counting any new patches before Open Starts). But, you'll be ahead of the rest of the OB crowd.