We were in early today, looking forward to a session on SharePoint with Bill Engolish. Sadly, that was cancelled so Andy and I sat in on the Server 2008 R2 overview session presented by Iain McDonald. That was very interesing, and we learned a bit more about BranchCache. It doesn’t look like it will replace WAN accelerators like Riverbved, because it doesn’t appear to function at their low level. However, it does a similar thing at the file level. The client requests a file from the remote server, which instead replies with hashes. The client PC the requests those hashes from the local cache, improving performance. The cache itself is built on request so does not need to be pre-populated (which is good). I think WAN accelerators have nothing to fear from this, but for smaller organisations or ones which aren’t able to put the accelerators in (perhaps their servers are hosted, for example) BranchCache looks like a very promising technology.