To get the update, simply logon to the store where you purchased the original version. You should see the update there.
Here's the official changelog for version 1.1:
- 15 heliports added (with a chart)
- ~200 Gold Coast buildings added
- Numerous landmarks added
- Trains in 17 railyards added
- Night textures enhanced
- ORBX compatibility fixes
- Minor autogen, texture, mesh, installer fixes
It's great to see developers adding more and more helipads on their scenery.
Drzewiecki Design has also confirmed they will be releasing an X-Plane version.