No one was surprised when Microsoft CEO Steve Ballmer and pals discussed the future of Windows Phone 7 multitasking during Monday’s keynote at Mobile World Congress — the company has covered its forthcoming multitasking solution for third-party apps on several occasions in the past. As we all know, it will work much like Apple’s solution. Apps will remain in a frozen state when sent to the background and will be able, in some instances, to utilize background APIs for functions such as music streaming. For the first time, however, Microsoft gave an extensive demonstration of a preliminary implementation of its solution during MWC. The demo shows off state-saving and simple task-switching, background music streaming, and it also shows Windows Phone 7’s upcoming task manager UI, which bears a striking resemblance to the “cards” UI seen on HP’s webOS. Hit the break for a video of Microsoft’s demo.