According to Screamscape, things aren't looking to great for next season. So far is seems like the Coastline expansion might not happen. Personally I don't think it costs much to add a new slide or two to an existing slide tower (probably $1 to 2 million tops). While I talked to someone in the park a while ago about how the economy would affect the Seaquel, he said the attraction was paid for and the only problem would be the scenery and how much could be bought. he also said he didn't really expect anything spectacular for next year.7/31/09) According to the latest rumors the previous 2010 expansion plans are now said to have been dropped or delayed by at least a year in an effort to recover a bit from the sour economy.
Whatever they want to do next year they must be working on it right now and laying it out (the date on Fahrenheit's blueprints said June 2007). I guess they had to toss the plans into the trash and start over.
My guess is nothing or some small improvements to a flat ride or two. That's it.