In fact, Google is making a point of calling this initial launch of Google+ enterprise features a "preview" that Apps administrators have the option to enable -- or not -- for their domain's end users at no additional charge until further notice. The Education edition is free, while the Business and Government editions cost $50 per user per year, or $5 per user per month.
A key, absent feature, according to Lepofsky, is an activity stream in employees' Google+ profiles where notifications of actions by their colleagues are displayed, such as when someone creates a document or posts a comment.
"They need broadcast notifications in the stream," he said.
Another Apps component that could be boosted through integration with Google+ is the Sites website-building application, Lepofsky said.
Bavor concurred that linking Google+ with Sites has a lot of upside potential.
"When you combine this tool [Sites] for structuring and organizing information, with the sharing capabilities of Google+, interesting things can happen," he said. "We're considering and evaluating all our options with Sites there."
Forrester's Koplowitz said that a full ESN version of Google+, along with the suite's existing functionality in Gmail, Docs and the other components, could make Apps very attractive to prospective customers.
However, Google isn't helping itself by being so tight-lipped about its road map and plans, because enterprise IT professionals need clear statements of commitment and direction from their vendors, he said.
Since the Apps components all started as consumer applications -- Gmail, Docs, Calendar, Sites -- their future destiny and development seem tied to their popularity among consumers, he said.
This is problematic in the case of Google+, which some industry observers maintain hasn't fulfilled the company's popularity expectations among consumers.
In the past year, Google has been anything but shy about axing products that it considers outdated, unpopular or redundant, an aggressive pruning effort mandated by CEO Larry Page.
"Google+ looks like a compelling enterprise offering, but, if it doesn't get traction in the consumer space, will Google continue to invest in it as an enterprise-only product? Will it pull the plug?" Koplowitz said. "That keeps me up at night a bit."
Bavor disputes the premise that Google+ is on shaky ground in the consumer market, pointing out that the social networking service has 150 million active users, with growth fueled by strong momentum.
He also said that the company's strategy for Google+ both among consumers and Apps users is to enmesh it in the fabric of Google's other products.
In fact, the push to make Google+ a ubiquitous presence across Google products is one element that will differentiate it from competing offerings, he said.
"We are deeply committed to Google+," he said. "We see it as being a cornerstone for the entire Google consumer and enterprise user experience."
Juan Carlos Perez covers enterprise communication/collaboration suites, operating systems, browsers and general technology breaking news for The IDG News Service. Follow Juan on Twitter at @JuanCPerezIDG.