I jumped on this. It's nice to be able to toss a terabyte or two into their cloud for cheap, and make sure I've got everything offsite in two places now, in addition to two onsite.
I'm not the biggest fan of Amazon, but I know their security levels are better than Dropbox, as well as being a shit ton cheaper. Carbonite is good too, but limited to one computer IIRC. This way I can just do a periodic dump from my NAS to the cloud.
That's a really good deal for unlimited storage.