As Google continue to change and rearrange Google Maps and Photospheres functionality comes and goes. In this instance Google has reinstated the ability to generate embed code for a published photosphere and this tutorial is no longer valid so it has been removed. Other options for embedding still remain and I'd recommend the following tutorials; Street View HTML Code Generator and Embed your Photospheres in your blog/webpage
(Old) Embed your Photospheres in your blog/webpage
