You can do but the moment you log into the Windows Store for example, it will log you into all apps including the SkyDrive one so it's all or nothing.
Also at the moment there is not an option to provision an 8.1 machine with a local account as well during the trial period. You must use an online windows account.
Maybe, I don't know. My concern is, that I would like to continue to use Windows 8, but not Skydrive. If there wouldn't be such a possibility, I could revert to Win 7 (although I don't like this idea, since Win 8 is superior product overall).
