I'm about to get my new 2011 MBP next week and it's coming with a 256gb internal SSD, but I was wondering if it's possible to use the disk entirely for Windows 7 (bootcamp'ed) & install Mac OS X on an external FW800 drive 'only'? Is this doable or are there any restrictions or limitations that require Mac OS X to be installed on the internal hdd? Basically my main work environment is Windows 7 but I need Mac OS X for other, fewer contracts aswell.
There is no reason why you can't do this up to and including Mac OS X 10.6.8 version of Boot Camp.
Do test command line booting control if you care about those things - but currently there is no restriction other than the Boot Camp volume must be on the internal drive. Mac OS X boots fine from other locations.