I sure hope that MS has their act together by the time this SP is released. I've had to install many, with no problems other than waiting. I'll make sure to have a good, current backup when the final SP is released, because my computer has and is running fine without it. If it screws up my desktop, I'll run without the SP, it's as simple as that. Vista with no SP ran for nearly four years, most likely the next version of Windows will be here before support is dropped for 7, even w/o the SP.
Windows 7 users aren't really getting anything out of this anyway, it's the server that will benefit. Personally, I believe it's a marketing ploy, there's those who refuses to buy a new OS until SP1 is released. Quite a few of them at that.