Microsoft may be gunning for the iPad with its future Windows 8 tablets, but in the mean time Redmond is beginning to roll out its signature productivity apps on the iPad. Microsoft released a OneNote app today, which will be followed by a Lync app, ZDNet’s Mary Jo Foley reports.

Microsoft has already been offering OneNote for iPhone since the beginning of the year, so it’s not a shocker, but it’s the latest example of the trend for Microsoft and other also rans to diversify their mobile stories. Microsoft has been working on other projects related to non-Windows mobile platforms, including its device management solution . RIM announced that it will be release software capable of managing non-BlackBerry devices. It also acquired cross-platform personal information management tools like Gist and Tungle. And of course last week HP announced that it will open source its mobile platform webOS, but the most significant piece of that release may actually be the Enyo framework, which will enable developers to build cross-platform applications.

Even HP, Microsoft and RIM lose the handset and operating system race, there are much larger prizes to win in the world of cloud services. Forbes recently covered a survey finding that mobile devices are driving cloud adoption even more than cost savings. That makes a ton of sense. If you think about it, RIM’s e-mail service was one of the first great hosted enterprise services. If your company is using BlackBerrys, chances are your e-mail is passing through RIM’s servers on the way to your device. Cloud services just make it much easier to deliver software and services to mobile devices reliably.

At the beginning of the year ServicesAngle editor Alex Williams wrote that tablets are great but it’s cloud storage that matters. Apple has certainly figured this out. That’s why it’s spent so much money building iCloud, and (reportedly) offered to buy Dropbox (and possibly Box as well) for $800 million. But I don’t think storage is the only game in town. I’ve speculated before that Microsoft can leverage Azure and Bing as a data-as-a-service that could provide the future foundation for the company. Google has always been interested in monetizing Android not through OS licenses, but through advertising and services.

Cloud services for mobile devices is an awfully big pie, and Microsoft, RIM and HP can all have a piece without having to own the operating system. In fact, the OS and mobile hardware are probably going to be increasingly commodified, with relatively little real business value for vendors. The big money will be in providing the services all those smart phones connect to.