My Google home page remained fine, I believe (I rarely use it). Here is a screen capture of mine, which I sorely need to update.
Yes, it is currently raining here...
It appears that those personalized home pages that lost their data were restored at about 4:30am (EST) this morning.
Google Guide Jaime wrote that he appreciated the reports:
Yikes! So sorry about this everyone... but thanks so much for coming here to report it. We're now in frantic-chase-down-this-bug mode here at the Googleplex, and I hope to have more info for you soon. For now, we're not entirely sure of this, but it's possible that changing your homepage theme might cause the problem. SO, if you still have your homepage intact, please avoid changing your theme until further notice.
The big question I know you'll all want answered is whether you'll get your homepage back once we sort things out... and the really honest answer is that I hope so, but I just don't know yet.
Thanks for all your patience and helpful details. I will update this thread as soon as I can. - Jaime
Later, Google Guide Cameron came in to say:
Thanks for letting us know that this problem isn't related to your theme - it's really helpful to get this info. Another piece of information that could help us sort this out is your approximate location; if you feel like sharing, that would be great!
That was out last word from Google and then at about 4:30am (EST), people began reporting their personalized settings have come back.