I'm assuming most will go with street kid to get that "rags to riches" story.
That would be a viable option and probably the option most aligning with the general plot or idea of you "rising up".
For me, I think, it is still the corporate background however. Since with it I doubt you obviously come from a background of being high up in a specific or key corporation we encounter in the game (what's the point of making a name in NC for yourself then if you are a big thing elsewhere?), I think I like the corporate world and it will be interesting to see what kinds of references and (prior) contacts you might encounter with such a background.
I also think it will offer more "political" (in corpo terms or that context) approaches to the world. In other words, if you pick a corpo background you'll obviously view certain things differently. While the main plot will be the same either way more or less, from a corpo background perspective I think you'd rather be interested in making a (new) name for yourself in NC and interact with or against the key players, as opposed to solely trying to get rich as street kid.
But of course a lot of that is assumption. Unless it was elaborated on in some interview and I missed it, we yet have to see how deep or important or game changing different backgrounds will be.
The Dragon Age example
Dragon Age I kinda did it in a good fashion background wise. Depending on your race and / or background you had a different game start centered around your specific background, from thief or street kid to being a mage or even nobility (would translate to corpo here I guess). Then some big plot event would happen, eventually throwing you into the main game and plot. Mind you, up until here it's all a bit like a tutorial and also a specific background and you'd already spend, I dunno, half an hour or one just in a scenario revolving around your background.
Then later throughout the main game you have different connections to different people and your individual background would factor in at one point at least once, if not at several times, meaning unique quests later on but also meeting or knowing unique people you'd have no real interaction or connection to with other backgrounds. The biggest impact I recall from one of the backgrounds was that if you picked nobility roots, depending on your later choices your character could move into a position to have or claim rights to the throne of Ferelden (the country you are in).
So long story short, I hope it might be similar here. We obviously can't expect a totally different game for each background as the main narrative has to be the same, but I expect a bit more than a few shallow references along the way. And if we look at the company here and also the given statements so far, I think we do not have to be disappointed in that regard.