The downside of
always using SSL for web
sites that require authentication is the need to buy SSL certificates.
I usually don't need anything stronger than "domain validation" (which
assures you that you're talking to the server you think you're talking
to, but says nothing about how trustworthy that server may be). I'm not
a fan of the current PKI, but there are now many more choices for cheap
SSL certificates than there were a few years ago.
The last time I bought a "proper" certificate was early last year, when
I upgraded the
30-day trial certificate I was using in development to a
certificate for production. That was fast and painless, and cost about
$40. (I've also used RapidSSL a few years before that.)
Recently, I learned that
(to whom I have now transferred all my domains from GoDaddy) is a
reseller for various SSL certificate providers, including GeoTrust (the
CA behind RapidSSL). Their pricing is very attractive, and I ordered a
three-year RapidSSL certificate for $9.95/year today. That was fast and
painless too (and it didn't include the phone verification step that my
earlier RapidSSL purchases did).
I'm happy with RapidSSL so far, but I still look forward to the day when
I can distribute encryption-only certificates through the DNS.