I can give you some perspective on your question. See below for some great groups that have lots of posts to get into more details and interact with the Jive community of clients.
I have worked on several large F1000 installations that have implemented Social Intranets with some key integration between Jive and the mothership for items such as single sign-on, profile loads, retention/archival as well as a host of Jive plugins that add some time/complexity to the set-up with large companies involved (sharepoint, mobile, MS office with internal VPN/fire wall rules, IP filtering etc..). In parallel the business side is working on communication/marketing plans, identifying "early adopters" and champions for the early rollout. All of this typically takes 4-5 months for a full integration as described to get the platform ready for users. Up until this point only the core team of maybe 10-20 people are on the system.
At the end of that phase you can start your early rollout. You don't want to launch a platform such as this to your whole company as many who are not real clear on the new tools will see nothing out there and that will make it harder for adoption. Instead, you seed your initial rollout with early adopters and champions who have some chops for this sort of platform. They probably were working with earlier social pilots in various pockets of your organization. Maybe they are marketing, communications or product areas that deal with social tools for their day job or in their personal life. This is typically a 2-3 month period. Toward the end of that period the communication and marketing pieces start to rollout out globally to create buzz and excitement as well as explain what this new platform is all about.
You asked for numbers so the pilots I have seen started with a few hundred (200-400) and after 2 months can grow to as high as 1,000 to 2,000 people as word gets out. You set-up the platform to accommodate everyone, however you only let grow based on interest. Once that period is complete and you have a great set of users geographically dispersed and ready to help evangelize you then can launch to the full organization. As a reference, the total populations I was working with were for these different organizations was in the 15,000 to 35,000 range just to give you an idea.
Search around the groups The specified item was not found. and Jive Internal Communities for lots of posts on these types of topics.
Social Edge Consulting
That's pretty much aligned with my thinking. I need to explain to certain people why they can't use it now for high level business collaboration when we haven't defined our security model or planned the training requirements or process yet! And why it's going to be at least 2-3 months for that to happen.
<laughing> let me know if you figure out how to explain it effectively. The one thing I can say is with each project the expectation initially is that once the platform is ready that it would be rolling out to everyone rather quickly. Over time, the team realizes this is not the right way to go to be effective and does what i described abvoe. But it takes a few sessions with a variety of people such as Jive strategy, client referrals (How did other similar sized companies do it),
So I don't think you can shortcut this process. Work on getting lots of client conversations set-up, which add enormous value for lots of reasons, as well as time with the Jive strategy experts who can also give a thoughtful approach.