If there's any intention to add live tv caching then ram should definitely be available to the user as a storage option. Although I don't really care about the feature, I don't mind if my ram is being used whereas I absolutely don't want a harddrive constantly running for it. Btw, I haven't paid more then $20 for 2x2GB sticks of ram in ages, though I always take advantage of MIR's on them. I actually have 8GB sitting new in the packaging but didn't want to pass up some great deals. :)
RAM + HDD = SSD
Overheating, spinning... it's something from dinosaurs' era :))