The attack has been reported to Microsoft. It affects both versions 7740 and 7720 of Windows Phone 7.5. When I first read this, I was wondering whether hackers were just expanding their already-prodigious knowledge of malware aimed at Windows OSes, but it's worth noting that, in the lab at least, similar attacks have already been dealt with on iOS and Android. What this really portends is that the black hats and vandals are shifting their gaze to mobile, along with the rest of the computing industry.
I have no doubt that it will be fixed and a patch will be disseminated forthwith. The big question is, with two decades of cat-and-mouse between OS vendors and hackers under their belts, will the mobile platforms be relatively hardened compared to the worst times, when it seemed that new PCs were instantly infected the moment they connected to the net for the first time, or are exploits like this just a speedbump, and mobile platforms will remain largely uncompromised in the real world?