Here's a sticky thread to post links to other preset downloads.

As of today, the busiest place to find links to presets is on the Flickr Aperture discussions, this thread.

Terry Chay's preset articles:
http://terrychay.com/article/aperture-3-presets....
http://terrychay.com/article/aperture-3-presets-...
http://terrychay.com/article/aperture-3-presets-...

Gary Seim, who is also maintaining a list of every preset he can find:
http://prophotoshow.net/seim_effects/2010/02/21/...
http://www.prophotoshow.net/blog/2010/02/21/aper...

El TiDy:
http://www.itsadirtyword.com/downloads/ApertureA... (direct link to file)

Nathan Smith:
http://www.smithfineart.com/home/2010/2/16/apert...

Gian Guido Zurli:
http://web.me.com/ilguidoz/Gian_Guido_Zurli_Phot...

Pavel Sigarteu's Sin City set:
http://www.flickr.com/photos/blueriotriver/43579...

The old Aperture Network/new MacCreate site has a bunch of preset packs which are free to premium subscribers:
http://premium.maccreate.com/2010/02/09/aperture...
http://premium.maccreate.com/2010/02/21/nikon-d3...
http://premium.maccreate.com/2010/02/22/nikon-d3...

Ian