Let two great plugins play great together. Use FeedWordPress to aggregate geodata generated by GeoMashup.
You must configure FeedWordPress to "Expose syndicated posts to formatting filters." Do this on the admin side at: Syndication > Posts & Links > Formatting > Formatting filters.
Feed GeoMashup scans posts syndicated by FeedWordPress for geodata in the RSS. When your site creates a new syndicated post, GeoMashup can use that data as location information for the post. In addition, Feed GeoMashup scans the incoming posts for maps that GeoMashup created in the original. When it finds such a map, it will replace it with a new [geo_mashup_map] shortcode. The shortcode on your site will probably not have the same settings as on the original. Your map will probably look different, but it will adhere to whatever preferences you have set up in your own GeoMashup options.
It might. It was created to operate on the GeoRSS generated by the GeoMashup plugin, but it should work on other similarly formatted feeds.
Look under "Syndication > Posts & Links" to find a Feed GeoMashup options box. Select an individual feed from the drop-down at the top of the same page to set feed-specific preferences.
Nothing. They will not be deleted, but neither will they be updated. If you set Feed GeoMashup to filter them, FeedWordPress will be affectively unaware of them.
= Can I filter an incoming feed to include mapped posts only from a limited area?
Yes. On the "Syndication > Posts & Links" settings page you can define limits to a range of longitudes and latitudes. Only posts mapped within the limits will be syndicated.