I know this will come as a shock to many of you - to hear me expressing an opinion about technology and on top of that recommending a Microsoft solution - but it occurred to me that the combination of Yammer and Sharepoint might just be the best thing for people trying to make social happen in their businesses.
I have been wary of the platform solutions like Jive and Tibbr for some time. They feel over engineered and over complicated - trying to do everything. I reckon users find interfaces that try to do too much confusing and that keeping things simple really matters. Being new to most businesses these platforms also take a lot of investment of time and money, requiring considerable effort to sell to your bosses worried about integration and security issues.
In contrast Yammer and Sharepoint make sense for a couple of big reasons. You still have the issue about using Yammer's servers but most IT departments are comfortable with Microsoft so you won't have to fight all the battles necessary to convince them to go with something new. You will also satisfy those who feel the need to manage and control. They can be kept busy fighting with Sharepoint while you can get on with generating viral fun in Yammer.
Maybe at some stage in the future Microsoft will make the two tools join up usefully but it doesn't really matter. You will have got going, generated some energy, and hopefully shifted the culture in the meantime - and for a lot less pain than might be the case otherwise.
I nearly didn't post this because I am genuinely not that interested in the tools and if you can make things happen using Jive or Tibbr then that is much better than them not happening at all. I just found it interesting that the combination of Yammer and Sharepoint might have become the lightweight, trojan mouse, alternative.