On Friday bzr-upload was officialy announced. In the blog announcement Martin tells the story of how this plugin was born. I'm proud to say "I was there!". I was sat at the table with them that evening as they discussed what was wanted, and what was possible. This was just one of the great things about the last sprint for me, and I was only there for two days.
Very often on the #bzr IRC channel we have users asking why bzr doesn't update the working tree on a remote machine, and what they can do about this. Very often it turns out that they are web developers who are looking to deploy a website, rather than just host the branch, and so the normal behaviour is kind of the opposite of what they want.
John wrote the push-and-update plugin to help with this, but it didn't fulfil all the needs, and requires ssh access, where web developers sometimes only have ftp access.
While bzr-upload does have some corner cases to be wary of, it's a great thing to have available. If you are web developer who is looking for a version control system for your code then consider bzr, it will hopefully suit your workflow very well.
Now, watch out for Martin's improvements to loggerhead, and Vincent's improvements to his kitchen.