Ideal size of boot partition for Windows Vista

[Men@discussions.microsoft.com Lung Men]

I have a new 500 GB SATA HDD on which I intend to install Windows vista and
am trying to decide on how best to partition the disk so that I have no
regret once everything is installed and running.

I have read pros and cons on the Web about the idea of a large single
partition for everything where Folders are used to separate Data,work files,
music ,videod etc. from the OS and the idea of multi partitions where the OS,
page file and applications are isolated in one partition (normally "C") and
everything else go in other partitions. Will it be acceptable if I partition
the disk in 3 primary partitions as follows:

C: 70 GB for OS, swapfile,programs etc.
D: 330 GB for work files, music, videos etc.
E: 100 GB for back up (Or eventually 2nd OS for dual boot)