I haven't once seen an intranet renew it's SSL certificate on time so it means at least once a year there will be a period of a week to six months that you have to click through a warning message.
Google switched the search to SSL and now nobody gets referrers for Google searches anymore.
When Google switched to SSL now I have trouble when I connect to public WiFi networks that want you to agree to something or log in to use the network -- it used to be you got redirected but now search just breaks without a sensible warning message.