This used to be easy enough - you'd just double-click the "FWD:" and delete it. With the new interface (April '13) you have to open the subject for editing and then delete it. When you do this, it will take your bcc section and remove it so you can easily copy to a list if customers without realizing so that they can see each other's addresses.
Give me back the old way, at least that almost worked! It used to be that you had to elect to take the new beta interfaces, now they are thrust upon you. Everything's broken for a few weeks and you just have to carry on - working as a tester.
There is a bit of a workaround. With Mac you still have to accept the new version of GMail. DON'T. I've switched to a Mac so that I can carry on working full speed while I wait for things to be fixed.
PS. It would be great to be able to turn off the FWD: flag across the board automatically. I use a lot of stock replies and "fliers" and don't want the flag - sin ce i am not actually forwarding, the message is from myself.