Why, sure a big ramdisk cost more.
But you get what you pay for, and €500 or $600 for 8x 8GB is certainly not out of reach of a lot of enthusiast, they even sell sets of 8x8 for enthusiast, i clearly remember paying something like around $600 for a UW SCSI card and one 4.5GB 7200rpm Quantum Atlas, and that was when money was still worth something!
So i think that's imho sort of a non argument, as anyone willing to build a real high end system can afford to get 32 or 64 GB of memory.
Sure it cost about 3x per GB as my 240GB RevoDrive 3 X2, but then its also way over 3x as fast.
And i not sure (dont know how hard it is to get review samples), but i think that there is a good chance that companies like Corsair or G.Skill cant waiting to send you a set for testing, as i think that they cant wait to sell these big kit's to enthusiast for RAMdisk use.
Because they are the only one's greasy enough to buy sets like these.
And a good review from SR will certainly help them to consider it more.
I just got my self a 3930K system with 64GB of memory.
Now with 58GB of ram, of the 64GB, for use as a ramdisk, ware also a portion is used for the swapfile (usually around 2~5GB), i still have to often swap directories from HDD to RAM to HDD, even now with 64GB. (from the 48GB in a i7 970 system)
But even do its not perfect, its still a lot faster then any SSD, it just takes a bit of work making batch files for the programs you wane run on the RAMDisk.
But once you make a proper batch file, you can use it as a template for other programs.
I now have Fire Fox and Anti virus(200MB) always on and WoW (31GB) semi-permanently on the ramdisk, and i still have 27GB free for swapfile and other programs.
And Robocopy is really your friend if you want to make batch files, to swap files between RAM and storage and visa versa.
Why do i hope more users are getting ramdisk?
As with the more users, the better the ramdisk software becomes, and hope one day i dont hav eto make my own batch files anymore, And that there comes a ramdisk catch software solution, as i see that as the next step in faster storage systems.
like you now have with SSDs for hot data and HDD for cold data, as in the OCZ Hybrid and the LSI MegaRAID CacheCade
Are there disadvantages for using a RAMdisk, sure, you really like a UPS, if you live somewhere ware whit so so stable electricity like me, and also, you real don't like to turn off your PC anymore, but then, mine looks great, and has pretty lights in him.