As an EETimes article points out, "ARM set up both systems to run the same operating system, the same browser and put them on the same high-speed corporate network and checked for responsiveness to the end-user. The Intel-based netbook seemed to beat the development board to display different websites most times, but not by very much. When it is considered that the netbook has a graphics processing unit and the development board does not, that is surprising result. Even more notable is that the Intel-based netbook is running at 1.6-GHz clock frequency the dual-core Cortex-A9 development is running at 500-MHz."
As ARM is surely going to keep pointing out to everyone, they don't have to beat Intel's raw performance to make a big splash in this market, because for these kinds of devices, speed isn't everything, and their promised power consumption advantage will surely be a major selling point. Of course, alternative OS fans will be cheering ARM on because Microsoft won't be able to buy their way into the market the easy way with bargain-basement XP licenses like they did with netbooks. Devices based on the Cortex-A9 will likely use the new crop of mobile OSes from Google, Intel, Nokia, etc, not to mention the innovations coming out of unknown upstarts.
Of course, performance is going to be important. The current crop of ARM chips doesn't have quite enough horsepower for a pleasant computing experience on larger mobile devices. But this video is certainly cause for hope that exciting new devices are on the horizon.