I agree, Oblivion or morrowind themselves as an online game might sorta suck, but maybe an Elderscrolls Online game that could take place in many of the different provinces and use the same type of graphics and physics system as Oblivion and such, change a few things, etc... By the time it is finished, everyone should have a compy that is able to run it smoothly, as well as a good enough internet connection... They would have to make many different servers to accomodate for the many people playing.
Now, on topic, Morrowind and Oblivion have a completely different system for leveling than Planeshift... In ES, you have to level up your major skills, chosen by your class at the beginning. Each skill is governed by a certain attribute. when you level your major skills enough, the ones you used the most determine how much automatic addition you get to the attributes that govern those skills, plus you get a few bonus ones to choose for yourself. In PS, you go out and fight to get the PP and level the skill up, then go to a trainer and spend money and pp to train that skill so that it can be leveled again... They are very different, unless I am mistaken.