The Zigduino has been sold out at SeeedStudio since the middle of August and here for a week. Luckily, we already had another run of boards being built when that happened. Our assembler tells me that he will be shipping the next run of Zigduinos today, which means we should have them available for sale sometime around the middle of next week. Three-quarters of that run is already spoken for, so if you need more, either join the zigduino-announce list or like us on Facebook so you can get the announcement of availability at the earliest possible time.
Since this run is likely to sell out so quickly, we're in the process of putting together a much larger run immediately afterwards. Watch this space for more information on that.
The sixteen channel driver shield has been sold out since the beginning of August. The only reason it's been out of stock so long is because International Rectifier has not been quick about making more of the part, the IPS6044G, that it's based around. Digikey has told us they should be getting their shipment of them in next week; we should have them back in stock a week or so after receiving them.