So, this just happened...
So, I was just restoring my iPhone 4 to stock iOS 6.1 after having stability issues with the evasi0n jailbreak, and noticed when I went into the App Store to update/download apps:
I appear to have the old App Store interface, pre-iOS 6. And it's not just the search page. Every page in the App Store, from updates to Featured to the App details pages themselves are all displaying as the old App Store interface. Now, I'm not complaining or anything. The old layout for search is far superior to the new iOS 6 interface, although I prefer the new Featured page design and the white background color to the old grey color.
So, is anyone else having this issue? I haven't tried restarting my phone or anything (mainly because this isn't a horrible issue to be having), but I'm curious if anyone else has had this issue.