Somebody on TTF summed it up well.
'Get the family stuff done and dusted - then you have your backbone in place, ready to bring on the big projects to bring in the thrill seekers'.
Four years of family work, to make sure that when they next do a big project, there's lots for the ankle-biters and grannies to be getting on with. It's also not that unusual an amount of time either.
Nemesis 1994, Oblivion 1998, air 2002, Rita 2005. I don't know why people get so upset about having to wait an extra year for a major new ride? Alton are seeing good returns for their current plan (though the market has been generally good this year anyway) - so why not stick with it?
The Sealife centre is likely to be pirate themed, and general feedback I've had (from madame_Furie and her online pals NOT involved in coaster enthusiasm) ) is exceptionally positive, and her friends (and their families) will definitely go to Alton if they put in a Sealife. It's just an additional string to their bow.
We knew 2009 was going to be another 'dead' year for enthusiasts, but it's worth it to keep churn levels low, and it gives them time to implement the 'next big thing', which even I think needs to come in 2010.