Here's what we know about the speaker:
1. He's pretty in love with his gal.
2. He's a poet.
3. We don't want to assume that the speaker is necessarily Edmund Spenser himself, but he's definitely a Spenser-ish dude.
4. He's got a pretty high opinion of his poetry-making skills.
5. In fact, his opinion of his skills is so high that he promises his gal that she will live forever through his verse, that in hundreds of years the world will still be talking about her.
6. The speaker seems pretty vain, and maybe even a little bit full of himself (and those poetry-skills). But hey, we're still talking about the speaker and his girlfriend today in the twenty-first century, so Spenser (ahem, the speaker) must have known what he was talking about all along.