Just to calm down some "FUD apocalypse" starting here slowly...

[wifi-hacking-theory-blabla]
...WPA decrypting via amazon cloud servers isn't anything special nor new. Roth just used dictionary-then-bruteforce attack on relatively short (6 characers, without special, punctation, etc) password and WPA (not WPA2, important!). He claims, that his modification of dict-bruteforce is 2.5x faster than old methods - this may be one of many small steps forward, but still, decrypting real password with regular lenght and numbers/upercase/lowercase/special combo would take ages. Literally. Not to mention WPA2

Still, there IS way to crack WPA/WPA2 passwords with silly SSID's and relatively long passwords (although not very long and complicated) - using so-called Rainbow Tables (if You dont know what it is, Wikipedia is Your friend). Succes depends also on table quality, so it's mainly good for VERY thorought prepared attacks. You can even create own tables for custom SSID, but that would take long time of big cloud sever to create. Although, You can even use it with N900 - if You take few terabyte-sized HDs with You and connect them via HEN Still, mhz and bus speed (limited USB speed) matters, cause device must go through partially creating (tens/hundreds)MILIONS of passwords, using half-created hashes from database.

Also, many people just use WPA/WPA2 password as delivered with their router from manufacturer, and in many (if not all) cases this password IS somehow related to router's serial number, and "random" SSID is sometimes also delivered from SN. For routers with such algorithm already revealed and NOT fixed/changed by manufacturer in next revision, getting key is easy as a pie and can be calculated in <second. It's really nasty thing, cause it give false aura of security. For router's owner, mostly
[/wifi-hacking-theory-blablabla]

... Anyway, guy with "phone" connected to terabyte HD via cable with USB adapter, doesn't look more suspicious thatn guy with a laptop. No, really. This happen all the time