Well, I got both at the exact same time on March 6, at 9am.
I'v already played completely through both and am about to restart Black.
What I did is play White first with Snivy and just go along with it, catching any and all pokemon I saw and absorbing every detail about the storyline. Then I started with Oshawott and traded five pokemon I wanted on my team that I had just hatched. Now i'm about to do the same. I'll keep doing it until I have one of each pokemon that is at least level fifty that i've trained from at most level five.