Historically I don't think this is normal. But from one of Matt Cutt's Blog entries I think we were being forewarned (although he presented it as business as usual) that it might take a month or two for all of the DCs to "synchronize?".
I don't know but I have never seen the index, back links and PR to fluctuate so drastically all at one time.
SERPS seem unchanged though. Really bizarre if you ask me.
Dan