You can download "the last supported version" if you want, the app store offers that now. And any apps already installed or purchased can be re-installed at a later date.
Right, but that only gives you an old version of the application - it doesn't include a matching version of the online service the application is connecting to. If the service has changed sufficiently, the old application may no longer work properly (or may just get a "too old, please upgrade" message).
