Just attended ID211 by Thomas Gumz from IBM on how you can use Domino as the source for your Update Site to provision features and plug-ins to Sametime 7.5, Expeditor and Notes 8. Lotus has built a really cool template, shipping with Notes 8, that allows you to run an Update Site out of a Notes database instead of using a file system based site. Very cool.
Thomas also mentioned that in Notes 8 you can provision features and plug-ins using NRPC instead of HTTP for remote sites. This will only work against Domino 8 servers since this is a new call that has been added to the NRPC protocol. The URL syntax will be something like nrpc://intranet.company.com/_<replica_id>/updatesite.nsf instead of the http:// equivalent.