Poking around the net, most of the references to this were from June. Most appear to be from the 14th to the 21st. Guess this feature didn't make it out of Beta, or could it be busy servers preventing it. ?
Syncing more than one app and downloading more than one at once is two different things. iTunes may look as if it's syncing multiple apps at once but it doesn't. iTunes queues up the apps then syncs them one by one as it does with all media. You may see the icons on your Springboard, but you can't launch them until they render (non-transparent).
The simultaneous downloading off applications isn't really a show stopping feature, IMO.
I agree. Launching iTunes on your desktop/laptop and updating your apps on your computer shows you how slow simultaneous downloads are, even with a fast connection. Apps downloaded one at a time appear to download quicker.