Yes, I found that too. It's convenient that up-arrow is context-specific. However, as a commenter on the blog said, the first suggestion avoids the "last logout wins" problem:
histappend is a must for me for any decent bash history usage; I like to set HISTCONTROL=ignoredups along with it to keep things clean and I increased HISTSIZE and HISTFILESIZE from the defaults.
A good bash history can often save your behind when trying to reconstruct what you did or when you have to run that one magic command you last ran 5 months ago...
