What pbiggar is saying is that hardware doesn't make sense to measure on the same timescale as software, not that it doesn't involve iteration. Think about the "time to ship" of sites like Facebook, Twitter, Youtube, etc and you start to see numbers closer to or within the 6 month time range.
FB, Twitter, and YT were incredibly small teams of less than a handful who knew exactly what they wanted to build. Expectations were minimal or non-existent when they launched. They didn't have a corporate board, a CEO, or Wall Street looking over their shoulders for monetization.
Looking from the outside, they seem to have a dysfunctional culture around shipping software with all the additional layers of management. Hopefully this changes and they have a chance producing meaningful products but I'm not hopeful.
