As in main quest side quests .. in simple terms if you played ob 150 hours you likely will play skyrim that long too as the content is about the same..
But the map may be bigger or smaller then ob.. most likely bigger as making a mountain as tall as the one they talk about wouldnt work very well in an ob sized map.. spoecialy as its only a tiny part of the skyrim map. They have to cram a giant mountain AND an even bigger canyon.. some grand forests and tundra and snow and blah blah blah AND 5 great cities and a bunch of towns... and some lakes and ruins and dragons and mamoths and and and..
Until they say skyrim is x square miles they arnt talking about a ,map. - unkown forum user (these arent my words but i think he said it best)