"It starts with the premise that the data services and architecture should be on servers. We call it cloud computing – they should be in a ‘cloud’ somewhere. And that if you have the right kind of browser or the right kind of access, it doesn’t matter whether you have a PC or a Mac or a mobile phone or a BlackBerry or what have you – or new devices still to be developed – you can get access to the cloud…"Clearly this is evidence that Google used the term widely within their ranks and with their customers, and that a solid argument could be make that the term was in "wide use" among the core techies that cared about the technology elsewhere. The rest of the market didn't care, but it was certainly not a term or slogan that was uniquely invented by Dell.
Still. No wonder the USPTO missed the "commonality" of the term initially.