The timescale Ericsson has put on the device is 2020—a long ways into the future, and maybe it doesn't have to be that far. After all, they've made one already—given the current pace of technological innovation, will it really take ten years to get something like this perfected and onto the mass market?
Well, maybe. The prototype they showcased was really just that—a prototype, merely demonstrating the idea. In practice, it could prove to be quite difficult. While in the last few years innovation has inspired everything to get quite small, the necessities aren't small enough to fit into a tiny little spider, between the battery and the hard drive space and the CPU and everything else required for a computer's functioning. Add in other features, like USB ports and wifi cards, and the idea of fitting all that into one tiny little cylinder seems far off. We're a long ways away from the sort of technology that the spider computer would demand.
Furthermore, there are issues of whether people would really convert to a laser-projected keyboard for everyday use. Pushing down physical keys is relatively ergonomic compared to slapping your fingers against a hard desk all day. There are also privacy concerns for use in public places, such as a cafe, as the only places to project your screen will be very public walls (unless the cafes of 2020 are quite a bit different as well.) Nor will it be easy to simply whip out a computer in places without clearly defined screens, such as in a car or sitting on the couch. This computer concept would not be universal for all computer use situations.
So, will this sort of computer really be used in 2020? Well, time will tell. In the meantime, keep checking up on the spider computer—this may just be the computer of the future.
Other articles on the spider computer concept:
Mobileandnotebook.com article (with pictures)
Slashgear.com article
Blog entry on Geek With Laptop.
Pocket Lint.com Article