I've suggested this to AdwordsAdvisor in the last few days (on the AdWords features I would like to see thread). Might be worth waiting a short while to see if anything comes of it.
Hi PCink - just saw this and thought I'd jump in to help set reasonable expectations.
Yes, I did pass your post along as a vote to include this functionality, since it has been on advertiser wish lists for quite some time.
As mentioned elsewhere, though, this is anything but straightforward - even though at first glance it seems that way.
I thought I'd ramble a little bit about feature requests in general, since it has been a while since I posted anything about the decision making process.
Very briefly, any change, regardless of how simple it may seem, actually requires a ton of work - ranging from engineering to updating the Help Center in more than 40 languages (including endless cross-referencing of every single page among thousands that even touches lightly on the feature) to training every single support person around the world in the nuances of the change.
For this reason, every requested feature (and these are taken quite seriously, by the way) has to be ruthlessly weighed against every other requested feature - and essentially put into a matrix that weighs and balances many factors that fall under these umbrellas: 1) What resources are required to make it happen, start to finish? and 2) How many advertisers will benefit from the finished product (and how much will they benefit)?
It'll probably seem obvious that if something is really tough to do, it'll had better benefit just about every advertiser - and benefit them in a truly meaningful way. Otherwise, it probably won't rise to the top of the list.
I mention this just so you will know that even if the idea being discussed here is filtered through the matrix and falls out looking like a winner, it will still take quite some time to make it happen.
All of which is a really long way of saying that waiting a short while before deciding whether or not to open a different account is not really necessary. ;)
I hope that makes sense.
AWA