I think this is a bad move. Like it or not, I know what SEOmoz is immediately. I've known what it was for years. It's a brand.
Moz makes me think of Mozilla, immediately. That's just how the brain works. It doesn't make say "Oh that must be SEOmoz just expanding their reach!"
Love it or not, we all know what MtGox is. It's a Bitcoin exchange. Even though the name is based on Magic the Gathering, that doesn't matter. If they became Gox, that would be meaningless despite their best intentions.
As always, I'm happy to be corrected by someone who knows more about this stuff than I do, but me thinks this is a bad idea.