Bluesea and Mike:
You can still enjoy your Keemun Mao Feng and Keemun Hao Ya A or B-2004 with full flavor if your vendor store the tea properly. Usually, black tea can be stored 1-2 years if it properly sealed.
Don't worry about Keemun. The reason, we are talking seriously about Long Jing Spring flush because it is green tea. Even for green tea- 1 full year is fine. Of course there is nothing like fresh harvested tea but for black tea 2004 production is fine.
Bluesea, You might see some changes year by year production. If you are totally stick with strong Keemun chocolaty, winy flavor then it will be difficult for you to enjoy tea for a long run. After all tea production depends on weather and the tea producers have no hand on it. Thick chocolaty Keemun were not widely available around 2004 compare to 2003 production. Upton's Keemun Hao Ya A-2003 was very nice with strong chocolaty flavor but not 2004 production. Harney & Sons offered a good Keemun Hao Ya A last year but it was very pricy. They are still selling that tea. If I remember correct, it was $22 or $25 for 100g. I love Keemun because of her dimensional taste such as- chocolaty, winey, floral, slight orchid-vanilla flavor, creamy finish, smoky, sweet etc, etc. You will never get any Keemun which can have all this taste, different grade Keemun release different taste, aroma and flavor. Imperial tea court is offering a wide range of Keemun and so far their Keemun Hao Ya A and Mao Feng is one of the best in the market right now.
The bottom line is- don't worry so much about Keemun as Long Jing-2005 production.
Ripon Maputo, Mozambique