I got iWork for free with my new 2010 MBP and it states $19.99 for me on the App Store, so my guess is, those of us who want the new update either have to buy a new Mac or cough up $20.
That is, unless someone knows of another way Apple has it released for us. I remember when there was an update, I think earlier this year, maybe last, where they had the update hidden on their website.
I think that's right. At least that is what I recall. If you have the previous "box" version you get updates through that to a point. If you want the "App Store" updates (which are newer) you have to buy through the App Store I think.