From TFA:
In addition, the physicists of the University of Innsbruck have found out that the decay rate of the atoms is not linear, as usually expected, but is proportional to the square of the number of the qubits. When several particles are entangled, the sensitivity of the system increases significantly.
This is somewhat troubling, isn't it? If the decay rate is quadratic in the number of qubits, and this turns out to be due to some fundamental physical law as opposed to limitations of the current technology, does that mean we can never have quantum computers with any significant amount of memory?
Not really. The researchers trapped and entangled 14 ions in a single ion trap. Quantum computers based on ion traps will have thousands of traps, with never more than one or two ions per trap. (Machines with hundreds of traps have been tested, ions moved between traps, etc.; see, e.g., [1]) It has been known since at least 1997 [2] that you can't have a scalable system with only a single ion trap (that would be true even were the decay rate quadratic in the number of ions per trap).
[1] Home, J. P. et al. Complete methods set for scalable ion trap quantum information
processing. Science 325, 1227–1230 (2009). arXiv:0907.1865 [quant-ph]
[2] Wineland, D.J. et al. Experimental issues in coherent quantum state manipulation
of trapped atomic ions. J. Res. Natl. Inst. Stand. Technol. 103, 259–328 (1998). arXiv:quant-ph/9710025
By the way, an arXiv link for this article is arXiv:1009.6126 [quant-ph].