As with spree to constantly update Google Wave, there modifications have been made into Google Waves to let people to unclog their inboxes from public waves. Earlier, there a number of google waves were used to be displayed at Inbox which was very annoying experience. However, now wave appears in inbox that is needed to be followed.

It can be understood in this manner as someone adds you directly to a wave or you contribute to a wave, you do directly follow a wave or automatically be following that wave.  But in case, you want to get updates for a particular wave then in that case you should hit follow button in the wave panel toolbar to follow.  There options for archived waves are also provided that removes waves from an inbox. Where a wave is updated to archive waves, it does appear on inbox once again. And it absolutely would be your choice to switch between following and unfollowing waves as much as to your opinion and choice.