Given recent news stories about loss of identity information from stolen laptops, it is certainly not paranoid to want to do this and if you tell me otherwise you are probably one of those guys trying to steal my identity information!
Read it at Linux Gazette
If your current setup is a more standard one that consists of a number of partitions for different purposes, don't worry. As part of the process, your machine too will be configured the same way. We are the Borg. Your devices will also be mapped out!