If you use the stable Debian release now it's time to start testing the transition. Make sure to get bugs that aren't discovered yet or vital to your operation reported or fixed.
Don't complain if something in Jessie that's important to you breaks, help now to make sure it won't.
I'm on Wheezy right now on my Ultrabook (using just a couple of backports, but almost exclusively Wheezy at the moment).
Are you saying that Wheezy users should migrate to Jessie to start finding bugs? Part of the reason I use Wheezy on this computer is because I know it's rock-solid and everything "just works". If I had another computer running Debian I would run Jessie or sid on it, but to be honest, I need to make sure that I have one computer that I can depend on reliably (which is why I use Debian stable to begin with).
If you're using Debian in a business environment, try upgrading a copy of your staging environment to Jessie to see what problems you encounter, so that they can be fixed before release.
If you're using it on your desktop or home servers, you could also upgrade in order to contribute testing to the project, but only if you're prepared for some things to potentially break.
I'm using jessie on my laptop and i am wondering what to do for the release switch. Should i change to "testing" now or stay on jessie, which becomes stable, and switch to the next testing later?
I stay with the toy story named releases. That way I never get a surprise upgrade when the meaning of "testing" changes. You almost never want that, since when the name changes it is the early days of testing.
Later when I need something from the next release, I'll upgrade to its name.
I think he means that he has 'jessie' listed in sources.list, rather than 'testing'. The latter will refer to a different version when jessie becomes stable, and again when the next one becomes stable.
That's really up to you. If you need your laptop to function, it's probably a good idea to stay on the newly released Jessie for a few weeks or months. After a release developers usually push major upgrades into the reposistories. That tends to break stuff.
After 4 months of hard work and joining both the Debian JavaScript Packaging team and the Debian Multimedia Packaging team, I have managed to get Groove Basin [1] accepted into Jessie [2], just in time for the freeze!
Awesome looking music player. I will certainly be trying out your project---and mille mercis for putting in the effort of getting it into Debian Jessie. That is really going above and beyond.
sid is then branched into a new codename which moves through the testing phase and then stable.
"Testing" and "stable" are rolling names which always points to the branch currently in the testing or stable phase, respectively.
(Well, simplified. There's also the experimental branch, but that's not something you can run. Then there's oldstable which is the phase after stable.)
Don't complain if something in Jessie that's important to you breaks, help now to make sure it won't.