This is quote from 'The Register'
"Basically, if you have an OEM machine connected to a server running WSUS [Windows Server Update Services] with the default settings it offers and installs SP1 automatically. This is killing machines and stopping them booting with a C00000034 fatal error," said Reg reader Simon, who has seen 15 machines downed by the flaw.
Full Article here.
Here's more from 'blogs.computerworld.com'
"Windows 7 Service Pack 1 - Don't install it, yet"
Full Article here.
I can't guarantee these articles or the authors, but Google the issue and make your own mind up. As Win7 SP1 doesn't seem to offer major enhancements (but, no doubt some will be waiting for what it does provide!) waiting seems to be safe approach.
Lol: I was keen to install it, I quote myself from another thread
"I typically wait until SP1 of any Microsoft release, (for me SP1 = released to scandalise the general public (ready or not!) & SP3 = Nearly mature (just still waiting for all the security fixes))".
Note to self: Tread carefully Glasshopper.