I really Love this Topic,
Just for starters I'll toss in I don't think Lyrics and Poetry are the same maybe Cousins.
Poetry has more forms than music has Genres
http://www.poetrysoup.com/forms_of_poetry/a
You could probably say the same for Lyrics.
I personally don't think Poetry in general makes good lyrics, but that is just me.
I prefer a more conversational approach. Very few people strool about speakin in rhymes
or chatting in Poetic Verse.
There are other things to consider as well like, not using Cliches' (I have a different opinion on this).
There is so much I want to say (and Learn) on this subject, but I'll leave it at this for now.
Oh Yea I almost forgot. What about Lyrics vs: Poetry in other Languages?