Here are some pictures by Terry of new Arca Swiss accessories for the Sony NEX. The cold shoe adapter uses the same interface as the standard flash. Screw it in and now you have a place for an accessory viewfinder, similar to the Sony FDA-SV1.
The Arca Swiss L-bracket provides a solid platform for attaching the NEX to a tripod. The camera can easily be changed from landscape to portrait orientation without moving the tripod head.
The Arca Swiss NEX Cold Shoe and NEX L-Bracket will be released next month. The pricing has not been announced.