LILO had a simple feature that allowed one to select the boot menu entry that should be used on the next reboot while in Linux, thus one could select the OS to be booted into on shutdown and didn't had to wait till the computer rebooted to the boot menu and select the next entry manually.
For Grub that feature has existed as unofficial patch as well.
This was quite some years ago. Has that feature made it into mainline Grub in the meantime? Is it available under Ubuntu and is there any way to integrate it with the GUI (i.e. have not only a "Reboot" entry, but a "Reboot into Windows" entry in the shutdown menu)?