Hmmm... maybe there is cause for concern, seeing that my replacements just hit Australia:

20-Aug-2010 Hong Kong Item posted and is being processed.
20-Aug-2010 Hong Kong In transit.
21-Aug-2010 Hong Kong Processed for departure.
21-Aug-2010 Hong Kong The item left Hong Kong for its destination on 22-Aug-2010
23-Aug-2010 Australia Arrived and is being processed.
23-Aug-2010 Australia Pending customs inspection.
23-Aug-2010 Australia In transit.

However, as per RK and HK Post's policies, I would still wait until at least 2 weeks have passed, otherwise you're just being a pest (IMHO of course).

How much did you guys order? Did you include a Megatron?