Yeah this is what someone said over on the Win7 Phone board about it..
sigh* Anyone who says "WP7 doesn't have multitasking" is taking a sledgehammer to a very nuanced topic.So, I'll do the same. "No, they're wrong, WP7 does have multitasking."
It depends on what you mean by multitasking.
1. Talk and use data at the same time. This depends on the carrier, not the phone. If you have GSM (AT&T, T-Mobile) then you can do both simultaneously. If you have Verizon or Sprint, no such luck.
2. Switch between apps without having to close out of the one you were just in. WP7 does this, too. Microsoft even mandates that there be a "back" button on the devices to make this even easier (though admittedly, I'd like to see a more full-fledged task manager).
3. Listen to music in the background while doing other stuff. Yep, WP7 does this. In fact, from any application you can hit the hardware volume rocker to make playback controls pop down.
So what are all of those reviews talking about? Well, they're drawing the extremely unimportant distinction between running in the background and being paused in the background. All native functionality (of which there is a lot more in WP7 than other phone OSes) will continue to run in the background. So if you had a core function that counted 1, 2, 3 etc. every second, you could start that function, go do something else, and the entire time you're in other apps it will still be counting. Third party apps by default will just pause. So if you start the app and then go do something else, it will still be at 3 (or whatever it was when you left the app). You WON'T have to start all over at 1.
I say "by default" because if the third party app actually needs to run in the background, Microsoft can allow this. For example, Pandora. You want to listen to your Pandora stations even when you're doing other things, right? Well that app can integrate into the Music+Video Hub, and essentially run as if it were a native function - it will run in the background, and you can control the playback by hitting the volume rocker, the same as with the Zune software.
Why the distinction? Two very good reasons. 1. Stability. If the developer of your favorite fart app is the one who decides whether it will run or pause in the background, experience tells us that they'll ALL be running in the background without regard for the integrity of the system. The result is you running out of memory and having to restart because that fart app is so important that it must ALWAYS be running in memory, even if you aren't using it. This is of course undesirable and so Microsoft wanted to step in to decide what runs in the background and what doesn't instead of leaving it up to the third party developers. 2. Battery life. The more stuff running in the background, the faster your phone guzzles down power. So again, it makes sense for Microsoft to decide what is important enough to run in the background and what can just pause.
Frankly, if Microsoft changed any of this and decided to go with quote, full multitasking, unquote, I would be very upset. I want my phone to be stable and to hold a charge for more than two hours. If those online reviews were even half-way honest, they'd have told you all this and probably praised Microsoft for making this decision.
