Why not just give it an RC1? Scared? It’s okay… I won’t hurt you. I’m here to help. I’m part of your target audience. Still scared? Go with "Beta".. I’ll understand. It’s not ready for full release. Again, I am here to help by giving you feedback so that, if your target audience (read: "me") thinks its a flop, they (again, "I") can let you know earlier than your actual release date. See? … We can work together to get you to where you want to be.
Anyway, the point is that your target audience knows its not yet supported. They don’t care whether it’s "beta", "release candidate", "alpha", "pre-alpha", "eap". That’s just there to show the world how comfortable you are with getting pre-release feedback from the target audience. Isn’t getting early and frequent feedback a good thing?
Oh yeah, by the way, SQL Server 2008 RC0 was released today.