No, you won't have to upgrade to 13.10 "no matter what". The recommended way to do upgrades is to always go to the next version (as that's what gets the majority of testing), but 13.04 makes no major changes (like replacing upstart) that would prevent it from directly upgrading to anything to which 12.04 or other recent versions could directly upgrade.
You won't 'be screwed" if you have hardware compatibility problems in 13.10; you simply boot an older kernel (since that's where the hardware drivers are). I've done it with several previous alphas - but users are unlikely to discover major problems by the time it gets to a final release. I already have one system using the 13.10 (saucy) repos now (though they have no updates beyond what's in the raring repos). Expect me and the others that enjoy the bleeding edge to find/report the problems so that you don't have to.
I'm not sure why any of this would be an issue anyway: When the OS keeps all your app settings in /home (which you should put on a separate partition), complete re-installs of newer/older versions take no more time than the upgrades.