I would like to see a bigger active patch antenna sized to the Tinydurino form factor for better signal quality.  Ugrading to a RTK capable GPS chip like the U-BLOX NEO-M8P or the SkyTraq S2525F8-BD-RTK to enable 1cm RTK accuracy.  Firmware should be compatible with RTKlib implemented on PCs and Android devices.  Having a project tutorial that combines the output of the GPS shield and the 9DOF shield using a kalman filter and a dead reckoning algorithm would help solve the gps signal quality issue.  The WiFi shield, or Bluetooth shield, or a new cellular modem shield would enable connection between the TinyRover and Base stations on android phones or cellular networks.