I have no real learning experiences with the norwegian language. But as far as I know vocabulary and alphabet just differs a little bit from swedish and there are no big differences in grammar or "regularity" which is (in my opinion) much better than in danish (What's so irregular about English?). However, I wouldn't call pronounciation and listening as easy - it's something that you need to getting used to. To put it in nutshell: There are more native Swedish speaker, but there shouldn't be any really big difference.

It is quite irregular when it comes to the sounds of the vowels. Some vowels have two sounds which are pronounced differently depending on the dialect. Different dialects also pronounce consonants differently. Scanians pronounce "R" like the Germans or Danes. Some dialects roll their R and some pronounce it very softly. Not to mention that Swedish got a few tonal words. "Anden" can mean two different things depending on your tone. And even though two consonants after a vowel imply a short wovel, there are words that should be pronounced with a short vowel even though it doesn't have two consonants following it. Norwegian is basically the same.