Unless stated otherwise, it's a port but with updated network functionality.
They've stated it has gameplay changes too. (Balance, new decks, different shop setup?) The truth is we just know very little about this new version period. All of the confusion is understandable, and 480p is a little hard to believe.
Honest question, wha was so good about this game that some want to see it make some form of a return? Never played the original.
Man, not even sure where to start. The basic gameplay is a third person multiplayer action game where you use psychic powers of your own choosing. Before matches you build what is essentially a deck of powers called an arsenal. These powers are doled out randomly three at a time during the match, adding a heavy strategic element and giving players enormous freedom. You can build your arsenal to do psychic kung-fu melee attacks, instead go for long-range sniping lasers, focus on defensive powers which erase opponent's abilities, try to control the battlefield on a larger scale (for example, making everybody regenerate psychic energy faster or slower), and all sorts of other possibilities. Battles take place in surreal environments with large amounts of gameplay-affecting destruction, like dropping ceilings on opponents or punching them through stone pillars.
This unique, exciting gameplay is coupled with great art, a very cool storyline in a strange post-apocalyptic setting,
a catchy and unusual soundtrack -- it's just an awesome experience.
For sake of fairness, Phantom Dust does have a couple major problems. There's some balance issues with certain arsenals (the Vicious Balance skill is something I'm especially expecting them to change around), and the solo campaign has a really strange structure to it that leads to a lot of wasted time. But get together with some friends for some matches and it's enormously fun, one of the best titles of its generation, a game that can easily become all consuming.