The addition of multi-admin functionality to Google+ brand pages will be hugely beneficial when it comes to page management for the many different brands and businesses that use them.
The feature is one that the vast majority of brands have been after for some time following the launch of pages on Google+; many have become familiar with marketing via brand pages on Facebook and as such, are accustomed to the flexibility afforded by Facebook's platform. Having the ability to add multiple administrators to a page provides numerous advantages, a few of which are outlined below.
Development - It's fairly likely that Google+ will eventually implement some sort of framework on its platform that will allow developers (in-house or at social media agencies) to create applications for Google+ pages, similar to the functionality currently available in Facebook. This will almost certainly require multi-admin access, or at the very least the lack of the new functionality would be a major barrier to developers. This is a pretty important reason for having multiple admins; Google+ will need fresh, unique content to grow enough to compete with Facebook, and developers can supply that content.
Customer services / moderation - one of the biggest concerns for brands with established communities within social media is how to deal with enquiries that come through the platforms and also any of the community who are unhappy with the brand for whatever reason. Multiple admin capabilities are essential for this activity so that multiple parties are able to monitor a brand page at the same time, depending on the size of the audience. This will be an essential aspect of social outreach activity as soon as a brand page starts to grow.
Posting from multiple parties - Similarly to customer services and moderation activity, posting from different parties will become considerably easier with multiple admins. Brands won't need to worry about needing to share login credentials across a range of different stakeholders, reducing any risk of confusion. In addition, any users guilty of posting stray posts could be identified through liaison with Google, mitigating any potential digital PR nightmares.
Security - Having one profile that is the sole administrator of a brand page on Google+ could easily be an accident waiting to happen. Should the profile be compromised, this would risk the whole brand page being compromised too with no other access points. Although having too many admin profiles would be just as much of a risk, it is certainly better than only having the one.
All in all, the new multi-admin functionality is certainly a step in the right direction for Google+ in its quest to rival Facebook. It will enable Google+ pages to be managed in a much more efficient way by their respective owners, with added flexibility that could see customer services integration and of course the applications that have become the staple of brand pages on Facebook.
However, this is only one of many steps that Google+ must take to grow. Pages will play a major role in how the network grows in 2012, which will be a pivotal year in defining whether the network is to be a success or a failure.