The 8MP camera on the Nokia N950 has "very similar image quality" to the Carl Zeiss branded camera on the N9 but the camera units are different. The front facing camera is in a different location but the same module is used for both devices.
Other differences include the lack of NFC module in the N950 and its digital compass isn't as accurate and the battery is slightly smaller (1320mAh vs. 1450mAh).
The software on the Nokia N950 isn't finalized and won't get an Over-the-Air update (but devs can flash it manually). Still, MeeGo is a very flexible platform and we're guessing it won't be long until someone ports the software from the N9 to the N950.