A FT checklist by Eric Sloof deffinatly worth reading before even considering FT for a server. Most importantly for me, No snapshots, only 1 vCPU, only thick disks, 2 NICs required for FT logging and no DRS for FT hosts will mean it is a show stopper for many installs.
http://www.ntpro.nl/blog/archives/1090-Fault-Tolerance-Checklist.html
Virtualised Reality 