As of tonight (Tuesday night), the winds have calmed down here in North County San Diego and the smoke is much lighter than it has been. They are lifting the evacuation orders for Carlsbad, so Legoland is in the clear and will hopefully reopen on Thursday.
This is directly from the front page of Legoland's website at http://www.legoland.com/California.htm:
LEGOLAND California will not open for business today out of respect and consideration for the firefighters as well as victims of the many fires currently burning in San Diego County. We are saddened by this situation that affects so much of California at this time and our thoughts and prayers go out to those families affected by the fires. LEGOLAND California will open for business Thursday as usual pending further developments in the news.
I am fairly certain the site will be updated with new information if the park will be closed on Thursday. If not, call the park's information line: 760-918-5346. And just incase that does not have the information you need, you can speak to a representative directly if you call: 760-438-5346 (which is the number you get to if you remain on the other line after the long recording).
As for SeaWorld, their website says they are going to be closed tomorrow, Wednesday Oct. 24. This is their statement from their website:
SeaWorld Closed Oct. 24, 2007
SeaWorld will be closed Wednesday Oct. 24 due to air quality concerns from the fires burning throughout San Diego County. While there are no fires in the park’s immediate vicinity, we feel this is the appropriate action. We also are adhering to the mayor’s request to keep the roadways clear of non-essential vehicles and to conserve the use of water and electricity.
The park’s animals are in good health. SeaWorld’s veterinarian team are keeping close watch on the animals’ and monitoring them around the clock.
At this time, it has not been determined when the park will reopen.
I hope this information helps and I hope if you come, you get to enjoy your trip!