I am not a lawyer but I have some experience with Internet domains.
In most countries there are laws protecting you and you can take court action if you have a good cause for claiming a domain (for example, a domain is using a trademark registered by you.) Keep in mind that there are people making a living from this, from buying and selling domains, from domain squatting, etc. You need to be careful. Never let a domain to expire. Even when you can claim it later if the law is with you, its painful and expensive, and you want to avoid conflicts. Something that often happens is that someone registers a name close or similar to yours, and use it either for getting your customers or for giving you a bad image etc. thats why some people also registers similar names. You can register your personal name as a trademark if you are going to use it as a domain name, since this is a strong argument in case of conflict.
In short, if the domain name is important to you, dont take it lightly, be careful, get informed, talk with a specialist if needed.