Why yes, it is very official and there's the amazing trailer to prove it.
After the somewhat of letdown that was RE5...well...in my opinion...judging from this trailer...I think Capcom will exponentially redeem themselves. It looks like Capcom has FINALLY done something VERY right. It's rather odd not feeling even an ounce of need to voice a complaint against Capcom because from this reveal, it looks like they're on the right track. What say you? The plot and what it seems to entail seems very interesting and pretty dark.
More info will be posted in this thread as it comes.
Oh, and Chris and Leon in the same game? Well good lord.