The main thing I have noticed from Nothern Rock going tats-up, is that online savers haven't been able to access thier funds since the shat hit the fan.
I'm not affected as I don't have any dealings with them, but should the credit crunch turn into the apocolyptic whore that some predict, then all of us with online accounts are going to be screwed.
I'm seriously considering moving all of my online accounts into branch accounts instead. Being British I'm fine with queuing for my money.