from :
http://blogs.msdn.com/bharry/archive/2009/10/01/tfs-2010-for-sourcesafe-users.aspx
this quote stuck out :
There are 3 main areas that we’ve focused on in 2010 to make TFS attractive to smaller teams:
1. Price – We’re not quite ready to announce the pricing and licensing for 2010 yet but I can tell you that it will be at least as easy and cost effective to get as SourceSafe has been. Stay tuned for more info on this.
If this is true (and I don’t think it is) it will greatly change the face of .net development organizations over the next few years.