I have been the youngest member of most of the sides I have joined and in many cases I still am, now 41 and dancing for 31 years!
Morris is not an attractive prospect for an incoming youth, when all the dancers are 40 - 60 and sporting beards, beerguts, dodgy knees and, in many cases, fairly enthenched attitudes to "tradition." And that's just the women! The fun element - good dancing, good music, beer and good company - is apparent once you are involved, which is why many dancers' children join and stay.
The boom in morris came in the sixties and seventies, when a lot of young men got involved because it was different, fitted in with the general folky music prevalent at the time, and people were less narrow-minded and more open to new ideas. Many of the new sides formed then and since have been as a result of disagreements and internecine strife, often over the dancing and approach to it.
The English are notorious for extracting the pee from anything and everything, so the chances of a Riverdance-style traditional revival happening are slim, because there will not be the support from on high - 5000 morris dancers for 2012 indeed!
The only way the morris can be continued and saved is through anarchy - for some young folk to find their own way of doing it, their own form of self-expression, and for others to see it and enjoy it. That anarchic element is the key to the Bedlams' success, for example.
Whatever it is that happens, I think one key element is that the traditionalists won't like it!