The previous comment highlights the most important factor - risk.My 5 year old Maple Trust GIC @ 4.55% matures for $17,000 on July 6/09.
You have to ask yourself why you are more comfortable with risk now than you were 5 years ago. Has something changed in your life that allows you to be able to eat a loss on your investments? If so then bonds, equities and other asset classes might be a better fit over GIC's.
I personally would not go for that 50:50 mix of the two holdings (but I'm not retired so its easy for me to say).