We are in the middle of our Kiln trial and are very concerned about support for named local branches. This is because there are many times when we wish to create a quick, lightweight branch to do some work in without the big hassle and wait of cloning a new repo and then creating an Eclipse project and having a bunch of different projects in Eclipse open at the same time. This is what we are trying to get away from by leaving SVN!!!
We already have one branch repo per developer in Kiln, which each developer checking out his repo to his own local box. The problem is that we want to use named branches on our local boxes in many cases rather than creating a clone (either locally, or in Kiln and checking that out from Kiln). When we try to do this we end up in a situation where even after we have merged our local branch back into default, we can't push back up to the server without forcing it (-f). Once we do this, our Kiln repo is now in a state where we can't push from the forced repo to any other because Kiln's web interface does have a -f option.
I think we can definitely understand why Kiln wouldn't want us pushing unmerged branches up to the repos on the server and then trying to push them around; we can accept this. What we want is to be able to push merged local branches back up to our repos. Without being able to do this it honestly feels like Kiln may be difficult for the workflow we have in mind.