It's no surprise that Google wants Google+ to be the one-stop destination for those signed up for the company's services — and also that it thinks Google+ is a particularly good service for photographers. Now, users of Google's Picasa service will be redirected to Google+ when they visit the Picasa homepage, the latest step in Google's quest to encourage users to try its still-nascent social network. Of course, Google knows that users often react negatively to changes like this, so it's including an option to switch back to the tried-and-true Picasa interface by clicking a small banner that pops up after the redirect (this adds a cookie to your browser to remember your preferences for the future).
The functionality has been in place for about a week, but Google has actually been redirecting photo viewers to Google+ rather than Picasa for some months now — the same set of photos are kept in sync across both services. Despite Picasa still living on, it's clear that Google wants to promote Google+ as much as possible and get users away from its older services that may get superseded down the line. Fortunately for those not willing to jump on the Google+ bandwagon, the company isn't forcing users to sign up if they want to continue using Picasa. If you don't have a Google+ account, you can keep using Picasa the same as always.