im quote sure (like 90%) that the thc is always degrading. Here is a quote staight from wikipedia.
"CBN is the primary product of THC degradation, and there is usually little of it in a fresh plant. CBN content increases as THC degrades in storage, and with exposure to light and air. It is only mildly psychoactive, and is perceived to be sedative or stupefying."

So yeah it will 'keep' but it wont be a good high. Heres rest of the link.
http://en.wikipedia.org/wiki/Cannabinoids
Mr. Elliot Reviewed by Mr. Elliot on . Storing Weed For Years - How to? I need to store weed for years... how can I do this? Should I vacum seal it and put it in the freezer? How long would this last? Let me know.... Peace:stoned: Rating: 5