Here's hoping that Elena's overhead attacks (F+MP, F+MK) retain the speed and range they have in 3S. I wouldn't want to see them be slowed down, and thereby rendered useless, like Ibuki's F+MK overhead. Her jumping target combos should be quite effective, much like Chun-Li's and Ibuki's. Her special moves all would translate nicely, though Lynx Tail (a breakdance-type, low-hitting move) could use some help.
She would probably have her Healing, but it couldn't be an Ultra. Ultras are gained by taking damage, and healing as a result wouldn't work too well. Healing would probably be her Super, which would be excellent. Having access to Healing regardless of Ultra choice would be amazing.
Ultra I would probably be Spinning Beat, which should have its uses, particularly as an anti-air. Ultra II would be my old favorite, Brave Dance. The problem is that Brave Dance was so good because it could be canceled from one of her best pokes, low MP. Without this cancel, it might be hard to actually catch someone with Brave Dance. I'm curious to see how Elena is able to land her Ultras.
Some of Hugo's normals would be great in SF4. I could imagine his low jab, low MP, and standing MP being really effective. His special grabs would all be the same as always, but I'm curious to see how well his clap and clothesline moves would work.
I see Hugo having Hammer Frenzy as his Super. For some reason, it makes sense to me for him to have a choice of a grounded grab ultra and an air-grab ultra. Hammer Frenzy, an actual striking move, would then be his Super. Much like Elena, having access to this Super regardless of Ultra choice would be a huge boon for Hugo.
Ultra I would be Gigas Breaker, which would be functionally no different from T. Hawk's, Gief's, and Hakan's grab Ultras. Ultra II would be Megaton Press, his air grab. This could be very useful in SF4. If Hugo is able to use Ultra II as an opponent falls from focus crumple, it could be very valuable.
The more I think about his style of play, the more I think he won't be in the game. His Patriot Circle (baton twirl move) has Rekka Ken inputs and would hit multiple times, ala Machine Gun Blow. His Mekong Delta rolling maneuvers would be like a quicker, backwards Abel roll, with potential follow-up attacks. He's got a wall bounce attack that's not unlike Fuerte's Picadillo Jump. His Stinger knife throw would be right at home in SF4, but could he still use his baton like Scrooge McDuck with D+MK?
His Super would probably be Steel Rain, where he throws knives into the air that rain down on the opponent. This would be his Super, because his other potential Supers would look so much better as more cinematic Ultras.
Ultra I would be his Take No Prisoner. This traditionally has to be blocked low, and involves a wire, a hook, and some of Rolento's cronies. Ultra II would be Mine Sweeper, which has Rolento roll backwards launching a series of mines that pull the opponent into the explosion. I really don't know how well these would work in the SF4 engine.