I'd say you might as well send it, as long as you send one to the current DM and make sure you mention to everyone that this is only in preparation for whenever your turn comes up. If you're working on your own campaign, it should take more than a week to prepare for things and I know that it helps to know what the others are being so you know how to begin. Heck, the people in my group have known that I'm working on a campaign and have already made characters for it, though we won't be starting for a while.
However, it all depends on the people. My group would understand, but I don't know about your group. It all depends on what you feel. If two members of your group believe it would be rude, it sounds like you should wait. You can always start preparing a little now anyway.