As can be seen with the screenshot, say that you have Windows7 installed, then you can choose Widows7 and when the computer reboots, and the boot-loader will automatically redirect you to Windows7. I'm not quite sure where, but I've seen this somewhere else actually. I think it was KDE sometime ago.. not sure though. Any opinions?. Anyhow, it would be pretty cool if they include a graphical boot loader configuration app as well.
Oh and, they won't release KDE 4.7 any sooner.. it's scheduled around July (27th to be precise), 2011.