Permitting pseudonymous access on Google+ may seem a dramatic about-face but is a necessary step in the next stage of the evolution of the service.
The announcement that Google+ will support pseudonyms, once the technicalities can be resolved, was equally unexpected and welcomed but not without a note of caution. It also changed the direction this post has taken having been started prior to the announcement.
Google+ has been maintaining the need for a "real names" policy because of the principles of trust required by an identity service as I have previously outlined. It is understandable that the company should want to err on the side of caution while creating a framework that could support multiple identity models and avoid some of the potential risks associated with anonymous content.
Some Google+ users have been echoing this call for caution in the hope that a relaxation of the rules on identity will not lead to an increase in spam posts, comments and other undesirable content.
Chris Poole AKA moot - the founder of notorious online forum 4chan - has been particularly vocal with regards to identity and stoked the fires further at this years Web 2.0 Summit where he compared our multifaceted, real-life personalities to a diamond rather than the simple mirror of the "fast-food version of identity" being imposed by the likes of Facebook and Google+.
Facebook was built on a specific premise and is therefore reliant on real names - without them it is worthless; Google+, however, is becoming more of an amalgam - as the social layer grows to incorporate additional Google services it makes sense that Google might have to relax their stance as other services can support Google's three means of use: unidentified (anonymous), pseudonymous and identified.
Vic Gundotra stated that the aim of Plus is to "activate the users of existing Google services" but the users may not feel comfortable being forced into exposing their real details when they have not previously been required to do so.
As is apparent from the announcements regarding both iGoogle and Reader, existing social functionality on any given service is being phased out and replaced by the Plus equivalent (if one exists) - Google, therefore, face a dilemma and presumably cannot run the risk of a user backlash should they lose the ability to communicate and be social without providing a real identity.
Google has a logistical challenge on its hands to manage this multi-tiered identification system and, as has been suggested, you wonder if there will still be a requirement to provide real details at the account level but with the ability to present a pseudonym to the public enabling Google to retain an element of control while still respecting the wishes of those who do not wish to reveal their true identity, for whatever reason, with the rest of the world. Any such system could finally make use of the Google+ nickname field.
Playing it safe
It is understandable that Google should want to launch Plus without pseudonymity. While not wishing to stereotype any specific group, the company would want to take reasonable steps to prevent the potential pitfalls of undesirable behaviour by those who may hide behind an alternative identity; building a stable, trustworthy base on which to build is imperative.
To use Poole's own argument against him, he would not interact as a son, spouse or parent in the same forum as that in which he operates as the "rabble-rousing hacker" moot so you can't blame Google for trying to make a distinction.
Now that Plus is established Google can take the next step of designing the framework upon which multiple identities can exist within the same service without impacting the experience or behaviour of the user regardless of the means of identification chosen.