Eh? Garage is nothing to do with current software -- it is a place to host shared projects. If there were any active projects in garage their owners could move them to some other service, of which there are plenty. Non-active projects would be archived with all their code available to anyone to download (as today) but with all the garage services terminated.
And the autobuilder is nothing to do with the repositories except that it is the only way, currently, to put packages into them. The repositories would be opened up so that the small number of developers who wanted to put software in them could do so directly, or via a volunteer who handles the occasional submission. Of course submissions would have to include both source and binary packages.
I am not proposing doing any of this now. My point is just that it is very likely that by the time Nokia pull funding, there will only be a small community of users and developers left, who can manage very well with just forums and a repository. That is a lot more than we had in the early days of the 770 community! There is no particular need to try to plan for keeping the current (expensive) infrastructure going indefinitely, as the community shrinks.