Remember the ash cloud last year, BA lost our luggage (and are constantly on strike), Sam ALWAYS gets bitten by something weird which requires medical treatment etc etc.
We are covered annually via Virgin, but individually everybody else needs to be covered in case anything goes "pete tong" - before, during or after the trip.
Some of you maybe covered via your current account etc, but its worth checking.
Money Saving Expert has a great page on Travel Insurance - please see below link (they also recommend Virgin as being the cheapest for worldwide travel under 50's, and High Risk for worldwide travel over 50's).