There are two extra roller coaster packs that can be found and downloaded from Chris Sawyer's website.
Not sure if they are any good yet, but I thought some people might be interested.
They are not already included in the GOG version are they? I didn't think so, but who knows.
The two download pages are below.

http://www.chrissawyergames.com/download1.htm

http://www.chrissawyergames.com/download2.htm

They are not included in the GOG download.

Jumpjet.info has more official stuff like this.

Great tnx!

Nice to Know! Thx! Downloading right now!

Excellent! Thanks for the info! :)

cool!

Thanks for the information and links.

Not sure if these are Sawyer, or Atari, or Contest winners or what.... but they're on the Atari FTP site in the RCT patches section:

ftp.atari.com/patches/rctycoon/Beastly.zip
ftp.atari.com/patches/rctycoon/Gem.zip
ftp.atari.com/patches/rctycoon/Original.zip
ftp.atari.com/patches/rctycoon/Woodies.zip

at a glance the phobias and catmice seem to be the same as sawyer's.

the rct-*dl.exe appear to be demos.. (English or Multi language)

Fort1 and Alton towers seem to be scenario updates already included in Deluxe.

The other 2 files seem to be binary patches (Wouldn't recommend using them, since the gog versions should already incorporate them.)