If the domain is important to you, I'd renew it. If you don't it will most likely drop, then you can register it somewhere else again, as if you never registered it before. Keep in mind that it will show up on every 'expired domain' list on the web, and if someone likes it, *they* might register it. In this case, it is gone, unless you can buy it back from them (I don't think you want to go there)...