I have just reached 15 days continuous uptime on my raspi (running adafruit packaged raspbian).
This raspi is running a custom twisted server which is communicating with a locally connectedJeeNode V6 (arduiono compatible with RFM12b 915Mhz transceiver). It is monitoring a remote Arduino Clone (Freetronics Eleven) which controls a 3 phase bore, several DS18B20 temp sensor (one immersed in water) and a Milone liquid level sensor.) The remote node manages water level in a 20m x 5m plant filter for a 120,000 litre capacity collection of 80 ponds growing water lilies and Koi.. as well as monitoring environmentals. Details are continously posted to cosm.
In addition I can monitor and control solar power LED flood lights with PIR sensors from the raspi remotely over the same wireless network.
The JeeNode is connected to the raspi via serial GPIO pins and is drawing power from the +5 pin on the raspi.
I am very impressed with the reliability and how easy it was to get things going especially given how new the hardware and distro's are.