This I fully agree on, that updates are usually needed anyway, except that we should be able to do incremental upgrades to the original source tree, not have to grab entire source trees or prebuilt, one-size-fits all binaries, at the moment we realize "hey - this distro didnt come with the src tree - let me donload it or burn it onto disc"
I'm not even sure what your point is here. :) Where's the "except" coming from? What's preventing you from doing this? You don't need the whole source tree at all -- just the source for the packages you happen to want to rebuild.
I meant to say that its desirable to get the incremental updates using any lightweight (or not) methods, say CVS, without downloading a whole new rpm (source tree) for each update - or even becoming dependent on rpm...
The incremental upgrades topics seems to make rpm retrieval unusable of we are pruning the tree.. would the update rpm also re-fill the tree by default? Using rpm-tree including/exclusion args seem harder than using CVS...