MySQL 5.1 version is stable in production environment

I am considering to use partitioning function provided in MySQL 5.1 version.

But 5.1 is development version according to my check on mysql site.

5.0 is current production version.

Can I use 5.1 in production environment without serious bugs , problems?

Thanks for your opinion.

It is now GA and stable enough for production use. Many of our clients are using it in production.