IMO eBay is a very unfair system - for the seller anyway. No other auction I know of ever stops at an absolute time. Like Akira said, if bids are received, time should be extended in case other people are willing to pay more. The Yahoo autions worked like this.
The best solution would be to have it selectable by the seller. If they want to sell an item quickly, before a certain date, fine. If they want a fairer price for the item, fine.
Of course, you could argue that the ability to snipe is one of the reasons that has made eBay so popular...