I have no real feelings one way or the other as far as who the female is, if I had to make a bet I would say Sherry seeing as she is actually relevant as a character.
The male character though, biases aside I would say is HUNK. He is a Mercenary, and infamous in his hand to hand ability. These notions that HUNK is established as a silent character are ill supported if you ask me. In RE 2 he didn't have much of a talking role because he had no one to really communicate with, directly more so, as most of his team members are dead or dying at the time. Though in Umbrella Chornicles we do get to here him speak somewhat in passing about a fellow USS memebers demise. On the note of USS he seems to be QUITE talkative to his fellow USS memebers in all the video seen of ORC. Secondly it's been speculated sometime now that HUNK may have some sort of immunity to the T-Virus which would account for why no matter how dangerous the mission he has always been able to return unharmed even when his entire team has gone under. Maybe his invulernability on missions can be attributed to something in his blood that makes him immune to the T-Virus. Also already having mercenary training and umbrella having fallen apart at the seams it would only make sense that HUNK would continue to live out his life as some sort of mercenary or possibly be picked up by one of the "coporations" out there. If Sherry had been under the care of one of them and this is her we are seeing in game then maybe HUNK got picked up for some high profile baby sitting duty, who knows for now really.
As for Steve I will simply say this. Steve was in Weskers possesion when he was presumed to be "dead" right? Is anyone but me very doubtful that Wesker would A) revive steve or B) let him escape if he managed to come back somehow. I doubt Wesker would leave any lose ends lying around and he probably kept his body somewhere for safe keeping or destroyed him. Though it is worth mentioning that Wesker did use the samples he gathered from Steve in DSC. Also what will the time gap from Code Veronica to 6 be? Suddenly becoming a mercanry as well seems a bit of a stretch if you ask me.
All in game decpitions of HUNK in cutscene art
This art I am very unsure about but I have come across is a number of times so it's your call really what you make of it, just remeber (and for all these pictures) These are depicting HUNK at the time of RE2-3 timeline-wise.
Also a little known fact that the toy company Moby **** released a short series of Resident Evil figures covering various characters and series. Of note there are 2 different model's they made for HUNK one having a removable mask. Take a look at the face and let me know what you guys think. Not sure how much I would invest in the info but it is an official RE action figure and this is HUNK
This is the official packaging of the toy in question
Take it all with a grain of salt, I just find all the speculation interesting. I'm mostly interested in comparing these pictures of HUNK's unmasked face to the screen shots of the mysterious new character.