What is the #1 reason to visit a project page? To download the source. Does the #2 reason come even close? No. So why in the world is the repo URL not on the front page, and easy for me to copy/paste into a terminal? Why? Github even has a button that will copy it to the clipboard for you!
Every time I get passed a github URL, it plonks me in a daunting page full of source code. If you scroll down a page or 2 sometimes you can see a text README file that tells you WTF the project is about.
On Google code, you get a nice UI, telling you about the project, bug tracker, discussions, binaries, AND IF YOU WANT IT the source code.
I think github is built for developers, whereas google code is built for developers and users.
Only after looking at these elements can you get a picture of the project which will tell you a lot about it. How is the support? Do developers even care? Are they serious at issues handling? Etc.
OSS suffers a lot from people who think they can just paste the code, change the implementation when they feel like it, etc.
This can't be stressed enough. A prospective user first-and-foremost wants to have an answer to the question "Is this piece of software worthy of my time?". If it fails to answer this question quickly, it will lose the user.
We are used to seeing this kind of ignorance from corporations: "Let's dump this piece of code online. A community will form and users will come by the millions." How many times has this worked?
Right now there are loads of interesting projects on github. Projects that will never be sucessful because they failed to do the extra effort required to "market" them.
The front page of a Google Project gives you no indication if the project is being maintained.
When I go to a project on Github this is my flow:
1) When was the last check in? 18 months ago? Pass. Recent? Yes, please.
2) Usage examples? No? Maybe if I really need you. Yes? I'll at least give you shot.
3) Copy git url to the clipboard and then clone it.
Google Code doesn't do a good job of any of these!
2) It's up to the project to show usage examples. Given that Google Code projects have a wiki page as the first thing you see, the examples can be in an even more prominent place than on GitHub.
3) Yeah, there's an extra click and some manual text selection here.
I don't know. I think it strikes a decent balance between letting developers get to the information they want and not scaring off non-technical users.
GitHub allows messaging, why not ping the author? Or create an issue "Needs Documentation? Or even contributing to docs?
While Google Code has some work to do on DVCS features, I still find it far more generally usable and thoughtfully designed than GitHub.