I've never payed attention to club Nintendo but after hearing you guys talk about it, I think I'm gonna get involved. The account I created years ago resets on June 30th (apparently, so does everyone's) (is that the same day for everyone or is that my anniversary?) so I'm waiting til July 1st to apply all my codes.
Do you have 600 coins worth to redeem? If so, I would do it because then you will become a Platinum member for this year and get the Platinum reward once it ships. The number of coins you earn doesn't reset from year to year, only your status as a Platinum or Gold member.