First off, I feel we need to step back here and realize that Samsung is not #1 right now because they make poopy-caa-caa phones. Yes, their lower end, inexpensive devices are cheap and unsupported as soon as they go out the door. But Samsung does high end devices amazingly well. Anyone who has owned a top end Sammy usually comes back for another top end Sammy, the best endorsement of a device. Also, remember Sammy was putting out the Focus/Omni series for WP 7 which were very well reviewed and enjoyed by those that owned them, myself being one.
That being said, what exactly outside of deep pockets does Sammy offer that Nokia doesn't? (Don't get me started on HTC. I am done with them until I am convinced they are a better company.) Low end? Nokia way better supports their devices. High end? Tell that story walking. MS is more responsible on the software side for problems. Nokia hardware and support paddles Sammy in most cases. Heck, I will take the Asha series feature phones if Nokia over Samsungs feature phones. Just higher quality, compressed data capabilities, support and updates, pick it.
Samsung could seriously mount a WP challenge. Of course- money talks and Samsung can put together a great device. But Nokia wouldn't blink. And in not blinking, Nokia would have already won.