I don't know how well gc.com works in other countries, but back here in Holland, me and a lot of contacts and friends aren't able to visit gc.com anymore since this particular update last Thursday.
The site goes online and than offline, more off than on, and when the connection is there, the site is as slow as it can be. Pretty hard to do any caching if it isn't loaded onto your gps, pretty hard to find new caches because the site is down all te time. It is also more than undoable to log any of your visits, to edit a cache you own, or to participate to problems that occur. All we get are server errors. So much for geocaching, how long is this going to take to resolve this issue??
Btw, the challanges, what on earth has that got to do with geocaching? Bad idea, drop it. Leave the imagination to the participators, if you come up with ideas like this, there are plenty of challenging caches undiscoverd everywhere and it is still growing. That is what we want.