This Windows Phone 7 demo at TechEd Middle East shows 2 interesting features.
The first is when the user switches to Internet Explorer, and the page is already loaded. This indicated that at the very least Internet Explorer suspends or even better fully multi-tasks in the background.
The next feature demoed is turning any web page into a tile. The tiles can however also be active, pulling data directly from the internet, and clearly another route for developers to multi-task on Windows Phone 7.
As of yet we do not know if Windows Phone 7 will allow full multi-tasking, but what has been shown already clearly shows, with clever developers, there will be a way to keep our phones constantly in contact with the outside world.