Google will start soon with indexing the maps and markers, see: googlegeodevelopers. You now can set with the Google Maps Plugin if you want your maps and marker indexed by Google (version >= 2.12m). You can set it default in the configuration of the plugin or as a parameter: googleindexing.
For example this map and marker is not indexed:
Keep in mind that the first map on the page will define if the maps on the page are indexed or not. It's only possible with the Google Maps API to set it on page level and not on map level.