Microsoft is reminding users that downloads of the release candidate of Windows 7 will be ceasing on 15 August. If you want to try out the OS on a test machine before its release, then the clock is ticking.
Also, if you're still running the Beta version, you're going to need to swap up to the RC pretty darn quick, because starting 1 July, the Beta will begin to reboot every 2 hours. On 1 August, it'll stop working entirely.
As previously reported on Pocket-lint, the final, boxed, version will be launched on 22 October. You won't be able to straight-upgrade (without a bit of hackery) from the Beta or the RC, or even from Windows XP. In fact the only OS you'll be able to upgrade to 7 from is Vista.
As a result, if you're running anything else, start backing up your data onto a removable drive now. The switch isn't tricky if you're prepared.