You know, I may not be that great and have a long ways to go (and lots to learn) . . . But I would kill for the Nikon D3s. Or possibly the Canon equivalent. POSSIBLY.

The huge boost in ISO alone is to die for. Add in the full frame and video and I am in love . . . metaphorically speaking.

There is just so much potential with it alone. But factor in that all that potential flows over to video!? And you can create pictures from the video!? That just adds a ton of awesome possibilities!

I could probably use this camera for the next 15+ years and not need any other reason to upgrade! Heck, unless something really innovative comes out I can't imagine anyone needing to upgrade from this in the next 15+ years.
(Okay, yes I can. Higher HD resolution and 3D. But that would cost a lot more than three times the amount this camera does.)

If you haven't checked out the nature video on YouTube that used the D3s, at the highest iso, than you should definitely check it out now.
Also check out the one from Canon. I believe it's under Nocht/Nacht.

Shows you how a little creativeness can create something truly amazing from these cameras.