Knowing Microsoft, they made the OSes continue the long tradition of installing side-by-side in dual boot configurations, and not "controlling the system." Ever since NT 3.0, Windows has worked fine in dual+ boot setups. It was only the Win9x and earlier lines that were designed to take over the system with a single-OS boot loader. However, MS even made it possible to dual boot them, if you installed an NT OS afterwards so the multiboot capable boot loader would be loaded into the MBR. The Windows NT installers automatically detects other MS operating systems and configures itself.
Apparently there is some issue with
XP deleting Vista system restore points during boot, however. There is a workaround involving installing on separate drives, instead of just partitions.
If you want to dual-boot alternative OSes (like Linux), you have to install a different boot loader (eg: GRUB), however. Even in that case, Windows will happily run in its own world when you boot into it, and not do anything to sabotage the other OS install.