I don't think it really matters
We'll all still know it means the same thing: their ranking isn't high enough.
WC or VIP will both = not ranked high enough
If you start calling it something different, you run into the problem of how many. Right now, there's a set number of WCs per tournament. So, if one of those turns into a VIP, do you add in another WC? So if Hingis makes a comeback at the 2010 US Open as a VIP, does another "loser" (as you put it) get put into the draw? So, if that happens, then who gets taken out of the draw, someone who is actually ranked high enough to play there?
And, do you automatically give former champs and number ones VIP entries? In my opinion, if someone like Ivanovic falls below the cut off and can't get into the tournament, she shouldn't automatically get a WC into a tournament. The situation with Henin, Clijsters, Hingis, even Navratilova when she returned a few years ago was that they were former champions making a comeback. The WC was supposed to help them out, and also give them a deserved spot in the main draw. But if someone like Ivanovic, who has had a complete collapse, can't even get into the main draw because she's playing like absolute shit, why should she get a WC or "VIP"? The same could be said of Kuznetsova, or Safina, etc. In other words, my point here is... Once you call it something different and set former champions apart from the "losers," it's expected that they will always get that special treatment. Where does it stop? Someone like Henin deserves a WC over any youngster or home player, but someone like Safina doesn't, the way she's playing now.