Mozilla has partnered with Telefonica and the Open is available through the carrier in several countries (Spain, Venezuela and Colombia), the eBay phones were sold directly to customers.
eBay UK is reporting 990 Open phones sold and eBay US says 985. There won't be any more units available until the next production run, but it's not clear when that will happen.
Note that the ZTE Open is still available through Telefonica-owned Movistar in Spain (for €70 including VAT) if you really wanted to buy one but missed the eBay sale.
There are other Firefox OS-powered phones too, Geeksphone Peak+ and the Alcatel One Touch Fire.
I received mine yesterday. The screen is awful, virtually no viewing angle without color distortion, the OS is basic, to say the least, and scrolling almost always over-scrolls making it very difficult to select anything from a list. The touchscreen ...
The really intetesting here it is that allow anybody that make some webpage to develop an app for the Firefox OS, at least they are at half the way to do that. Can you say the same from the complex, propietary and restrictive development tools of Ios...
What is wrong with the OS? There aren't many apps yet, but that's not Mozilla's fault.