I'm currently dual-booting Windows 7 and 8 (Consumer Preview). If I install Ubuntu, will I be able to switch between all three operating systems?
You should be able to do so - grub will recognise and add them to the boot list for you.
The ubuntu install will break windows 8 so back up boot files (with 7 the first two files are usually in a separate 100MB boot partition) /bootmgr /Boot/BCD /Windows/System32/winload.exe You could make up a recovery disc from within (both)windows before trying to install ubuntu (this will save you uninstalling ubuntu and windows 8 in order to reinstall/repair windows 8)
This thread here http://ubuntuforums.org/showthread.php?t=1955926 could help to understand what happens and how to fix or prevent some of the issues that are preventing windows being unhappy sharing a machine with ubuntu.
Ans is YES
for doing this
1 - make sure it will not go beyond the 4 primary parition if it so then your pc will not boot up
2 - you can make extra partion by gparted tool but it will not more than 4 in case of primary partition while other extented parition is allowed
3 - after having the sufficient space for windows 8 then
4 - install windows 8
5 - now you notice that only windows 7 and 8 is listed in windows boot loader
6 - now you have 2 option