You will need to purchase an ADS-B receiver. We're developing our integration using a Radenna SkyRadar unit, and hope to have this done in the next couple of months. Following that we will begin testing other units for compatibility, and tweaking our code if needed.
Weather will include nexred radar, winds aloft, metars, and a couple other things. And we will overlay the radar on the maps.
We intend to include support for viewing other traffic, however the FAA is a bit vague on how that will work. It seems they are only going to broadcast traffic that is near an an aircraft with an adsb transceiver. That means if you are within range of one of those planes, you will get traffic data. What I don't know is what that "range" is. One official said 25nm...if that is the case, then anytime you are in a congested area such as a class B halo you are sure to have traffic data. But maybe not in the middle of nowhere.
Hope this helps,
Walter