Since Day1, I have always said that there will be free upgrades, and there will be upgrades that are charged for. When Prolific took over the business end and the SereneScreen website, they kept exactly the same policy. So far, all upgrades have been free. The 3D background upgrade, one of the hardest things ever attempted in the history of mankind
, will be free. The new user interface will be free. All bug fixes will be free.
The Creature Packs, which will contain several exotic (and unbelievably difficult to create) creatures will not be free. The price has not been set yet, but I'm thinking around $9.95
As far as updates not being talked about, you're wrong. They are talked about all the time. Feeding the fish is planned for the 3D background version, as are several other perks.