As for startups, BTCChina was huge this past year.
Bitstamp's input looks more important now that I think of it.
Bitstamp's website was down all day yesterday, couldn't get any money out, doesn't give me a good feeling.
I have a deposit with them, too, nothing big, but a little worried as well.
Yeah same here, i wouldn't lose much but Bitstamp is the only way I have set up to convert my Btc into fiat atm.