It means that it will sell. They are still bidding on it because it doesn't close until tonight. The bidders won't drop out. It might sell for more than the bid is showing at the moment.
I agree with jomifl. I sell a lot on eBay. Send the eventual buyer an invoice via eBay as soon as the auction finishes. Never post anything until you have cleared payment (even if they send a cheque, people have to wait until the cheque's cleared my bank), then always get a proof of postage from the PO when you mail it, in case it doesn't arrive the other end. Having said that, it's very rare that people don't pay IMO.