Are service packs really passe?

Are there any real reasons -- other than psychological ones -- to wait for a first service pack (SP) of Windows Vista before deploying?

Microsoft's position, since the company released Vista to manufacturing last year, has been that users didn't need delay their deployments until the delivery of SP1 because the team would push out new updates and fixes continually via Windows Update, Windows Server Update Services (WSUS) and other patching mechanisms. Just this week, in fact, Microsoft delivered via Windows Update two mega hotfix packs (performance and compatibility) for Windows Vista that include many of the fixes that will be part of Vista Service Pack (SP) 1, which now is due in Q1 2008.

But some say service packs still do matter. Over on the Windows Connected blog, Josh Phillips has a list of why some users still prefer to wait for a service pack before deploying.

First on Phillips' list: Service packs are more thoroughly and rigorously tested than individual udpates. There's also the convenience factor. For enterprise users, a single update like a service pack is much easier to manage in a controlled way than are lots of incremental updates.

If you're waiting for SP1 to deploy Vista, what are your reasons? Is it more than just habit?