It's fresh, it's packed, and it's superior to the original.
Did they do that? Well, this is everything the original game was and more. It is clearly superior, which is only more obvious if you actually played the original. It retains the beautiful visuals from before and even improved the detail and beauty of the stages in the background. Everything about the art style of Super SFIV, right down to the main menu backgrounds, is the sweetest visual eye candy you've tasted in a fighter. One thing that could have been improved was the arcade mode cutscenes. They were kind of corny in the original game, but at least they were actual scenes. They have been replaced with still pictures containing spoken dialogue over them. A minor nitpick, but a negative aspect regardless. They brought back the car and barrel stages for Arcade mode. Fun little stuff, but not some kind of huge improvement nor could I ever consider anything about it to be a flaw.
The online options and replay value of this game are robust. Street Fighter IV had ranked match, player match, and an eventual Championship Mode. Not until Championship Mode DLC came was online play fruitful and satisfying. Somehow that was omitted from Super, but there is a Tournament Mode DLC coming in the next two months. What we did get however, was a much needed uphaul to the ranked mode. Instead of the silly battle point system that didn't really work, you now get Player Points, and each individual character you use gets Battle Points. PP will display how well you are doing at the time and requires you to win streaks of matches at a time to keep it high. BP goes down much slower but essentially measures your experience with that character. These also gain and lower directly based on the PP and BP of your opponent, and how decisively you won, requiring actual skilled players to go up in the ranks.
The other online offerings are Endless Battle and Team Battle. Both bring a much needed perk to Street Fighter. Endless Battle is an 8-player, winner stays lobby. Players get in line for a match and if you win, you take on everyone else in line, if you lose, you have to watch and wait your turn again. Nothing like that classic arcade experience. Team Battle is a little different. Also containing a maximum of 8 players to the lobby, you have up to four-on-four fights, where the losing player of the team is eliminated and the winner faces the next in line on the other team. Very fun modes here.
The Replay Channel is the remedy to Street Fighter IV's silly attempt at saving replays. You still have to do well (but not as astronomically well) to upload replays in Super, but you can go to the Battle Log and save any of your last 30 fights, and even rename them and rate them if you like. While watching an Endless or Team Battle match you can also press the Back/Select button to save that match. My only nitpick here is that you have to do it while the match is still in progress and can't save after it's finished. So you have to make the decision as the match is going on as to whether or not it's to your liking to watch later. This replay system is beautiful. You can again invite friends to fill up to an 8-player lobby and watch random replays or the ones saved on your own channel. The only way this could be better is if you could have a file share type of system (similar to Halo) to display your favorite and best moments for people to see online.
Capcom even improved the Challenge Mode for this game, as well as unlockables. You start the game with all the characters unlocked and instead of having to do tons of trials to get titles, icons, colors, and taunts, all you really have to do is play the game and the character that you like. Time Attack and Survival modes are gone and now the only stuff left in Challenge Mode are character trials. But wait! Before you get the idea that this means all it has are ridiculously impossible combos for you to button mash and fail at, remember that I said this was improved. Instead of Capcom trying to teach players impractical and frustrating stuff, they have made the trials overall easier because you are learning things that are actually viable in a real match with a player. There are maybe 2-3 really difficult trials that each character has but I found myself doing almost every single one in that sitting, and that paid off.
All the new characters play well and are very different and fun while the original roster has had some much needed tweaks and everyone feels a lot more able to hold their own against most of the cast now. In a day and age where everything is about DLC every ten seconds, Capcom has given us a less than full price expansion that improves on it's predecessor in every single way imaginable. You can't go wrong with that. I firmly believed Street Fighter IV was the best fighting game around, but it does not come anywhere close to the quality of Super Street FIghter IV, and that is impressive.