Aw come on, why do you need an explanation for something so simple?
How can anyone call having 4 apps open together on a quad core CPU "multitasking"? That's 1 app per core = 4 CPUs (4 computers) each doing their own thing, as opposed to 4 apps running simultaniously on a single core CPU.

But, anyway, like I've said in the past, I have not yet found anything out there that even comes close to a replacement for the N900 where usefulness is concerned, especially for my line of work. I'd quite happily replace the back cover for one without NOKIA stamped in it and scratch it off the front bezel, it's an embarrassment having them there.