The characters, being touted as series regulars for next year, show that World War II (or at least that time period) will be a key part of the second season, possibly throwing fuel on the fire of rumors that Alan Scott, the Golden Age Green Lantern, will be the caped mystery hero who appears at the end of Season One.
Here's how TVLine describes the pair...
"A male in his late-20s to mid-30s is being sought to play a guy who grew up in the shadow of his World War II hero grandfather and has used a Han Solo-like facade to conceal his insecurity — until, that is, the development of super powers enables him to love up to his family legacy."
And "the female member of an elite paramilitary team living in the 1940s. An African-American, she is scrutinized in her time for both her gender and race and thus has worked twice as hard to be a perfect soldier. That said, she blames herself for — and aims to avenge — the death of a team member for whom she had repressed feelings."
In the case of that second character, Lady Blackhawk seems like a likely candidate. It's interesting that she's avenging her unrequited love, which begs a question: could this be a new version of one of Hawkgirl's reincarnations? Certainly we've seen one of those already in the Old West episode.
That first character could be...well, any number of people with JSA ties. During Geoff Johns's run on JSA, he introduced a lot of legacy characters. Sand is a solid possibility, as is Steel (not John Henry Irons, a different one).
Hopefully we'll find out more, soon. The CW's upfront presentation is coming along in just about a week...!