As we reported earlier Meego Wiki have published the way to Dual boot Meego and Maemo. Here in the video below Carsten Munk @stskeeps shows the dual boot of Maemo and Meego in his N900.
Stskeeps [Official maintainer of the MeeGo Nokia N900 hardware adaptation] in Talk.Maemo.org said
MeeGo 1.1 isn’t out yet, give us a little bit of time
What will happen if things go right:
* Package install from extras-devel that enables the u-boot boot loader.
* Upon startup, if there is a SD card that’s bootable, it will boot the SD card, with MeeGo. Otherwise, it will boot Maemo.
Better wait if you need to go in the soft way by installing the package from extras-devel 
.
Via MeegoExperts and Simon for youtube upload.
is there any option like OS choices menu in windows in which we have to select which os we want to run while booting..!!
Not now but will there in uboot
That is some creepy ambient music in the background. Sheesh! O.O