Google has taken the first major step in bringing Android Market on Google TV devices. Company yesterday released the preview of Google TV Add-on for the Android SDK. This preview will help developers to build apps that support Google TV, however this add-on does not contain all features of Google TV.
A full version is expected to be released soon. TV emulation is currently supported on Linux with KVM only; other operating systems will get the support in the near future.
Devs can also tweak their existing apps to bring support for the idiot box using the addon.
You can learn more about Google TV addon here.