Upper Deck has announced that this Gen Con they're going to be bringing back their Vs. System card game system via their new Vs. System 2PCG. "2PCG" stands for 2-Player Card Game. The new box game will come with everything that two players need to make decks and start playing. No additional purchases should be required and, in fact, there won't be any booster packs sold, anyway, since everything is coming right in the main box.
For a few more details, the box will be $49.99 and come with 400 cards (4 copies of the regular cards for your deck, and one copy each of "Main Character" cards, which you can only have one of per deck, so there's no need for extra). A standard deck will be 60 cards and have a maximum of 4 of any particular card in a deck. So you can see that you'll get more than enough to make your own deck, and plenty to make several others (though not all of them, obviously, will be able to have 4 of every card, if they're shared between a couple decks).
Upper Deck has said that the game will play pretty much like the old Vs. System game, but obviously modified to fix any issues that had come up as well as working to make it more "new player friendly." And while this first set will be based on Marvel characters, there are plans to expand it out to the various IPs that Upper Deck has access to.