Ward,
First welcome to the forums.
You don't have to wait for the Installer version. You can grab the current version with the Clock/Crystal right here:
http://www.fish-byte.com/MA3Beta.zip
It is unknown exactly when the Installer version will be upgraded to include these new features. If you want to stay up to date with the latest features, then download the beta and just write it over top of your existing version.
You purchased MA3 which means you are covered at least until Marine Aquarium 3 comes out of beta and possibly for years to come.
There will be some add-ons like Creatures (Coral Shrimp, Eels, etc.) at some point down the road which will cost a little bit extra.