Version Support

No problem at all: Edgy is in the normal support lifetime of 18 months (every version has the same, except the ones labeled as LTS). Dapper Long Term Support has 5 year on server support because many users seek for a stable version of software and want to stick to it, just getting major bugs and/or security fixes (e.g.: you have an application that runs ok in dapper and don't see the need to change but you're forced if you don't get at least security patchs). Ubuntu is just given you that option of keeping your current version.