I've tried Ramdisk before, if you bench it the numbers are insane however if you think you can start loading games from ram I can tell you now it does lower loading times but not as much as you might think. It's not the fault of the Ram but at these sort of speeds you hit the limit of what the software can deliver, given that we not likely to be using Ram permanent for storage any time soon developers won't be investing time into improving optimisation.
The best application for Ramdisk that I can see would be for production pro's who work with video files and large graphics, the Ramdisk can be used a temporary scratch disk while your working on a project. At the end of the day you can then save your working file back to a hard drive and load it back the next day. The problem at the moment is to get the best out of this you need really a ton ram and ram is not exactly super cheap at the moment.