Google adds a test of a secured search page: Google offers SSL/TLS security for its Gmail service (through a browser or client protocols). It's extended that in a trial for searching. SSL/TLS provides a (so far) unbreakable encryption tunnel between a client (such as a Web browser) and a server.
If you're using a VPN service or a VPN connection to your company when working on an open hotspot network, securing search isn't terribly important. And securing search alone isn't enough; a secured proxy Web server that lets you redirect all queries would be better.
However, for those without the resources to use a VPN (or pay for a service like Anonymizer) could turn to Google for at least a bit of protection.
And if you live under a regime in which searches are dangerous, a secured search--if not blocked--is a conduit to freed information.