You know, if I was going by the instructions in 1.5.1 to 2.6, I would be convinced that I need to remove the blogs.dir directory from their server. I'm about 99 percent sure that is NOT what we all want people to do when they upgrade.
I'm doing the upgrade tonight. I cannot wait to enjoy the new functionality, and install Buddy Press later.
As somone who does tech support over the phone, I like to give callers the specific instructions, leaving no room for error. Nervous tech support users appreciate it, while those who think they already know how to do everything do NOT.
Just my two cents.