I could see myself using this when I'm killing time answering questions on Stack Overflow and don't want to launch SQL Management Studio to test out my answers, or if I'm on a machine where it's not available. I was pleased to see it supports the declare table variables in MSSQL. Are there limitations on commands, etc?
I don't allow stored procedures or other programming (custom functions, triggers, etc...), because I worry about the danger of opening up that to the whole world. It should be pretty much open for any other standard database+sql commands you would need to do.