What's on the first post looks more like gadgets than multitasking to me -- like old world Macs. You still need to code the floating "widgets" separately ; they cannot be normal applications. So exactly like DAs in old PalmOS.

In fact, both Android and iOS can do something better which is to run actual applications in windows:
http://www.youtube.com/watch?v=db2UbDEgzEA

But you are still limited to the usual design limitations of a mostly monotasking environment. You cannot open more than one window from the same application, so no composing of multiple emails, no multiple chat windows, no copying and pasting of word documents...

Garbage.