UPDATE (3/3/2014): SilverStripe 3.1.3 and 3.0.9 stable are out now!
We are heading ever closer to an official SilverStripe 3.1.3 stable release. Yay!
As the release process goes we have recently rolled out release candidates rc1 and rc2 for you to download and try out. The release candidate process gives us a change to stablise the codebase, fix any obvious (or not so obvious) bugs and generally ensure that by the time the next stable version is available you can be sure that deploying it on your websites is a painless as possible.
Of course, whenever rolling out an updated core of SilverStripe it would be worth testing your application (here's hoping you write some unit or integration tests!). As far as simply getting the code if you are a user of 'composer' it is pretty quick process.
Update your composer.json file which should reside in your project code to include the stability flag "@RC" to the Framework and CMS requirements. This will allow you to get each subsequent release canditdate simply by running "composer update" in the terminal (just remember to drop this flag from your composer.json file once the stable release becomes available!).
"require": { "silverstripe/cms": "3.1.*@RC", "silverstripe/framework": "3.1.*@RC", }
If you find any bugs or issues in these RC releases make sure to let us know about them.
For CMS issues log them at http://github.com/silverstripe/silverstripe-framework/issues/new
For Framework issues log them at https://github.com/silverstripe/silverstripe-cms/issues/new
3.1.3 stable coming soon!