This is the only reason I decided to use Github after avoiding Sourceforge and their ilk for the past decade and a half.
But why github? Why not gitorious.org?
If github goes away, I still have my code, but I lose any issues people have filed on the site, and I lose being able to easily check on forks of my projects where people might be doing interesting stuff.
I had been using gitorius.org, but moved to github for all the things other than git that makes one public git host different from another.
It'd be nice of all those related items were also in a repo, easy to pull.
http://www.anchor.com.au/blog/2009/09/github-designing-succe...
Now, Github probably wouldn't encourage total reliance on their service. Git is fundamentally distributed, so this doesn't have to be a problem. Still, the Github service is an integral part of many developers' workflow, and I do agree with the above commenter that I'm not sold on the idea of trusting remote servers with integral steps in my workflow.
For open-projects, it's a FANTASTIC platform... no doubt about it.
For a corporate closed project, I honestly would not use github - not because of any feature or lack of them, but because it's a hosted service. I want control over where my code sits, period - if only for the same reason as most hosted services - a subpoena or similar court order can be served against the provider with no notification to the owner of the data. This is the #1 reason one should be careful basing one's business on hosted services.
edit: that makes no sense